fix a fixme by sinking various target-specific directives down into
the appropriate subclasses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77815 91177308-0d34-0410-b5e6-96231b3b80d8

coff also doesn't have a ReadOnlySection yet, (!)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77814 91177308-0d34-0410-b5e6-96231b3b80d8

coff doesn't set a .bss seciton, so this is dead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77813 91177308-0d34-0410-b5e6-96231b3b80d8

it turns out that isWeak() was basically dead anyway.  Kill off SectionInfo :-/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77812 91177308-0d34-0410-b5e6-96231b3b80d8

don't use isWeak anymore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77810 91177308-0d34-0410-b5e6-96231b3b80d8

fix a layering violation by moving SectionKind out to its own header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77808 91177308-0d34-0410-b5e6-96231b3b80d8

Minor whitespace tidiness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77807 91177308-0d34-0410-b5e6-96231b3b80d8

Fix typos in comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77806 91177308-0d34-0410-b5e6-96231b3b80d8

with the previous refactoring, fixme fixed!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77805 91177308-0d34-0410-b5e6-96231b3b80d8

update for API change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77804 91177308-0d34-0410-b5e6-96231b3b80d8

Change SectionKind to be a property that is true of a *section*, it
should have no state that is specific to particular globals in the
section.  In this case, it means the removal of the "isWeak" and
"ExplicitSection" bits.  MCSection uses the new form of SectionKind.

To handle isWeak, I introduced a new SectionInfo class, which is
SectionKind + isWeak, and it is used by the part of the code generator
that does classification of a specific global.

The ExplicitSection disappears.  It is moved onto MCSection as a new
"IsDirective" bit.  Since the Name of a section is either a section
or directive, it makes sense to keep this bit in MCSection.  Ultimately
the creator of MCSection should canonicalize (e.g.) .text to whatever
the actual section is.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77803 91177308-0d34-0410-b5e6-96231b3b80d8

add a note about the build bots

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77796 91177308-0d34-0410-b5e6-96231b3b80d8

Minor code cleanups.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77795 91177308-0d34-0410-b5e6-96231b3b80d8

Print the target flags as an int instead of a char, as they aren't
actually characters.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77794 91177308-0d34-0410-b5e6-96231b3b80d8

Use the default copy ctor and copy-assignment operators.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77793 91177308-0d34-0410-b5e6-96231b3b80d8

Add nounwind to this test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77792 91177308-0d34-0410-b5e6-96231b3b80d8

Add newline at end of file to remove gcc warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77791 91177308-0d34-0410-b5e6-96231b3b80d8

Remove now empty unit test directory.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77790 91177308-0d34-0410-b5e6-96231b3b80d8

daniel says it's fine to nuke this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77789 91177308-0d34-0410-b5e6-96231b3b80d8

update for new api

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77788 91177308-0d34-0410-b5e6-96231b3b80d8

All MCSections are now required to have a SectionKind.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77787 91177308-0d34-0410-b5e6-96231b3b80d8

Hack to make this test work on platforms which aren't Macs.  Fixing this
myself because I'm getting tired of seeing the red buildbots, which have
been red since 5:30PM PDT last night.

Proposed supplement to developer policy: committers should make sure to
be around to watch for buildbot failures after committing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77785 91177308-0d34-0410-b5e6-96231b3b80d8

Workaround a couple of Darwin assembler bugs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77781 91177308-0d34-0410-b5e6-96231b3b80d8

Give MachineFunctionAnalysis a destructor so it can verify that
that it released its allocated memory.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77775 91177308-0d34-0410-b5e6-96231b3b80d8

Delete a redundant variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77774 91177308-0d34-0410-b5e6-96231b3b80d8

Minor code simplifications.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77769 91177308-0d34-0410-b5e6-96231b3b80d8

Minor code simplifications.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77768 91177308-0d34-0410-b5e6-96231b3b80d8

Avoid a problem with ulimit on Solaris & friends, patch by Edward O'Callaghan!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77767 91177308-0d34-0410-b5e6-96231b3b80d8

Split t2MOVCCs since some assemblers do not recognize mov shifted register alias with predicate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77764 91177308-0d34-0410-b5e6-96231b3b80d8

Make default ctor for ImmutableSet::iterator public.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77762 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mc: More quoted identifier support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77761 91177308-0d34-0410-b5e6-96231b3b80d8

SelectionDAGISel no longer needs to check hasAvailableExternallyLinkage,
as it is now a MachineFunctionPass, and MachineFunctionPass now handles
this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77760 91177308-0d34-0410-b5e6-96231b3b80d8

Make UnreachableMachineBlockElim preserve MachineDominatorTree and
MachineLoopInfo.

llc now runs MachineLoopInfo and MachineDominatorTree only twice, instead
of three times.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77759 91177308-0d34-0410-b5e6-96231b3b80d8

The X86 maximal stack alignment calculator preserves the CFG. Also,
be more careful about the return value of runOnMachineFunction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77758 91177308-0d34-0410-b5e6-96231b3b80d8

X86 floating-point passes don't modify the CFG.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77757 91177308-0d34-0410-b5e6-96231b3b80d8

Fix Thumb2 function call isel. Thumb1 and Thumb2 should share the same
instructions for calls since BL and BLX are always 32-bit long and BX is always
16-bit long.

Also, we should be using BLX to call external function stubs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77756 91177308-0d34-0410-b5e6-96231b3b80d8

Use setPreservesAll in X86CodeEmitter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77755 91177308-0d34-0410-b5e6-96231b3b80d8

Use setPreservesAll and setPreservesCFG in CodeGen passes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77754 91177308-0d34-0410-b5e6-96231b3b80d8

SelectionDAGISel does not "preserve all", since it makes lots of changes
to the MachineFunction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77753 91177308-0d34-0410-b5e6-96231b3b80d8

Use a range insert instead of an explicit loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77752 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mc: Add -triple, and fix some typos

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77750 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mc: Fix .s output to quote section & symbol names when necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77749 91177308-0d34-0410-b5e6-96231b3b80d8

Privatize all but one of the remaining constant tables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77748 91177308-0d34-0410-b5e6-96231b3b80d8

Allow target intrinsics that return multiple values, i.e., struct types,
in SelectionDAGLowering::visitTargetIntrinsic.

This removes a bit of special-case code for vector types.  After staring
at it for a while, I managed to convince myself that it is not necessary.
The only case where TLI.getValueType() differs from MVT::getMVT is for iPTR,
so this code could potentially make a difference for a vector of pointers.
But, it looks like that is not supported.  Calling TLI.getValueType() on
a vector of pointers leads to the following sequence of calls:

TargetLowering::getValueType
MVT::getMVT
MVT::getVectorVT(iPTR, num elements)
MVT::getExtendedVectorVT
MVT::getTypeForMVT for iPTR
assertion fails "Type is not extended!"

So, unless I'm really missing something, this bit of code is irrelevant to
the current version of LLVM, which is consistent with the fact that I don't
see this code in other similar places.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77747 91177308-0d34-0410-b5e6-96231b3b80d8

Add a warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77746 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mc: A few more parsing / match tweaks.
 - Operands which are just a label should be parsed as immediates, not memory
   operands (from the assembler perspective).

 - Match a few more flavors of immediates.

 - Distinguish match functions for memory operands which don't take a segment
   register.

 - We match the .s for "hello world" now!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77745 91177308-0d34-0410-b5e6-96231b3b80d8

t2BR_JT is mov pc, it's 2 byte long, not 4.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77744 91177308-0d34-0410-b5e6-96231b3b80d8

Thumb2 movcc need .w suffix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77743 91177308-0d34-0410-b5e6-96231b3b80d8

add some comments on how this is *supposed* to work.  We don't
need the PreferredEHDataFormat hook, but I have yet-more refactoring to
do before I can zap it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77742 91177308-0d34-0410-b5e6-96231b3b80d8

rearrange a conditional.  Even if this weren't #if 0'd out, this would
have no functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77741 91177308-0d34-0410-b5e6-96231b3b80d8

Simplify operand padding by keying off tabs in the asm stream.  If
padding is disabled, tabs get replaced by spaces except in the case of
the first operand, where the tab is output to line up the operands after
the mnemonics.

Add some better comments and eliminate redundant code.

Fix some testcases to not assume tabs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77740 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mc: Support quoted identifiers.
 - Uses MCAsmToken::getIdentifier which returns the (sub)string representing the
   meaningfull contents a string or identifier token.

 - Directives aren't done yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77739 91177308-0d34-0410-b5e6-96231b3b80d8

PreferredEHDataFormat is always call with data and global, but this whole
thing is #if0'd out anyway.  Just simplify the code by reducing the interface.
Not deleting this is essential for Bill's continuing happiness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77736 91177308-0d34-0410-b5e6-96231b3b80d8

Fix unit tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77734 91177308-0d34-0410-b5e6-96231b3b80d8

Move the metadata constructors back to 2.5 syntax.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77733 91177308-0d34-0410-b5e6-96231b3b80d8

Update unittest for LLVM API change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77730 91177308-0d34-0410-b5e6-96231b3b80d8

LibCallAliasAnalysis doesn't use TargetData.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77729 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mc/X86: Sketch match functions for immediates and memory operands.

Also, change scale value to always be 1 when unspecified to machine MachineInst
encoding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77728 91177308-0d34-0410-b5e6-96231b3b80d8

Make TargetData optional in MemoryDependenceAnalysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77727 91177308-0d34-0410-b5e6-96231b3b80d8

move emitUsedDirectiveFor to TargetLoweringObjectFile and rename it to
indicate that it is a predicate, not an emitter.  This eliminates TAI
dependencies on Mangler and GlobalValue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77726 91177308-0d34-0410-b5e6-96231b3b80d8

Remove an unnecessary header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77725 91177308-0d34-0410-b5e6-96231b3b80d8

remove the PPCLinuxTargetAsmInfo implementation of PreferredEHDataFormat,
because it just calls the default impl.

Remove the PPCDarwinTargetAsmInfo version of PreferredEHDataFormat because
it just returns DW_EH_PE_absptr unless on 10.6.  However, 10.6 doesn't support
PPC, so the default impl is just fine.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77724 91177308-0d34-0410-b5e6-96231b3b80d8

remove a pointless override.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77723 91177308-0d34-0410-b5e6-96231b3b80d8

Move a few more APIs back to 2.5 forms.  The only remaining ones left to change back are
metadata related, which I'm waiting on to avoid conflicting with Devang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77721 91177308-0d34-0410-b5e6-96231b3b80d8

Fix GVN's debug output, now that operator<< on Value* doesn't print
a trailing newline.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77719 91177308-0d34-0410-b5e6-96231b3b80d8

Whitespace and 80-col cleanup.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77718 91177308-0d34-0410-b5e6-96231b3b80d8

- Convert the rest of the DOUTs to DEBUG+errs().
- One formatting change.

No intended functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77717 91177308-0d34-0410-b5e6-96231b3b80d8

PR4662: Fix a crash introduced by the recent LLVMContext changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77716 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a typo in a comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77715 91177308-0d34-0410-b5e6-96231b3b80d8

Adjust unit test for the MCSection changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77714 91177308-0d34-0410-b5e6-96231b3b80d8

Delete spurious semicolons.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77712 91177308-0d34-0410-b5e6-96231b3b80d8

Fix build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77711 91177308-0d34-0410-b5e6-96231b3b80d8

Update CMake files.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77709 91177308-0d34-0410-b5e6-96231b3b80d8

switch off of 'Section' onto MCSection.  We're not properly using
MCSection subclasses yet, but this is a step in the right direction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77708 91177308-0d34-0410-b5e6-96231b3b80d8

Remove Annotation.h, which is no longer used in the LLVM tree.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77706 91177308-0d34-0410-b5e6-96231b3b80d8

Until we have a "ALIGN" pseudo instruction, have asm printer emitted a .align
to ensure the instruction that follows a TBB (when the number of table entries
is odd) is 2-byte aligned.
Patch by Sandeep Patel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77705 91177308-0d34-0410-b5e6-96231b3b80d8

MachineFunction no longer needs Annotation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77704 91177308-0d34-0410-b5e6-96231b3b80d8

- Teach TBB / TBH offset limits are 510 and 131070 respectively since the offset
  is scaled by two.
- Teach GetInstSizeInBytes about TBB and TBH.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77701 91177308-0d34-0410-b5e6-96231b3b80d8

fix some more issues where we expected GetSection to do "get or create"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77700 91177308-0d34-0410-b5e6-96231b3b80d8

Fix printing of Alloca instructions with null operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77697 91177308-0d34-0410-b5e6-96231b3b80d8

Fix some problems with ASTCallbackVH in its use as a DenseMap key.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77696 91177308-0d34-0410-b5e6-96231b3b80d8

Teach ValueHandleBase to treat DenseMap's special Empty and Tombstone
values the same way it treats null pointers. This is needed to allow
CallbackVH to be used as a key in a DenseMap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77695 91177308-0d34-0410-b5e6-96231b3b80d8

Process DbgDeclareInst.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77694 91177308-0d34-0410-b5e6-96231b3b80d8

Split DenseMapInfo into a separate header file, so that it can be
included separately.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77693 91177308-0d34-0410-b5e6-96231b3b80d8

Normalize target registration code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77692 91177308-0d34-0410-b5e6-96231b3b80d8

Reapply r77654 with a fix: MachineFunctionPass's getAnalysisUsage
shouldn't do AU.setPreservesCFG(), because even though CodeGen passes
don't modify the LLVM IR CFG, they may modify the MachineFunction CFG,
and passes like MachineLoop are registered with isCFGOnly set to true.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77691 91177308-0d34-0410-b5e6-96231b3b80d8

fix a bunch of failing tests now that MCContext::GetSection doesn't create sections.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77689 91177308-0d34-0410-b5e6-96231b3b80d8

refactor section construction in TLOF to be through an explicit
initialize method, which can be called when an MCContext is available.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77687 91177308-0d34-0410-b5e6-96231b3b80d8

Move getTrue() and getFalse() to 2.5-like APIs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77685 91177308-0d34-0410-b5e6-96231b3b80d8

split MCSection stuff out to its own .cpp file, add a new
MCSectionWithKind subclass of MCSection.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77684 91177308-0d34-0410-b5e6-96231b3b80d8

move the sectionkind and section classes to TargetLoweringObjectFile.h

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77681 91177308-0d34-0410-b5e6-96231b3b80d8

create sections with MCSection::Create instead of Context->getOrCreateSection.
This is needed to allow polymorphic sections.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77680 91177308-0d34-0410-b5e6-96231b3b80d8

fix PR4650: we only track sizes for certain objects, so only put something
into the mergable section if it is one of our special cases.  This could
obviously be improved, but this is the minimal fix and restores us to the
previous behavior.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77679 91177308-0d34-0410-b5e6-96231b3b80d8

Work around a dangling pointer dereference when enumerating NamedMDNodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77675 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a struct/class mismatch, to silence a MSVC warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77673 91177308-0d34-0410-b5e6-96231b3b80d8

define target names for std libcalls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77667 91177308-0d34-0410-b5e6-96231b3b80d8

Add this test back, the check pattern was too strict.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77662 91177308-0d34-0410-b5e6-96231b3b80d8

Revert r77654, it appears to be causing llvm-gcc bootstrap failures, and many
failures when building assorted projects with clang.

--- Reverse-merging r77654 into '.':
U    include/llvm/CodeGen/Passes.h
U    include/llvm/CodeGen/MachineFunctionPass.h
U    include/llvm/CodeGen/MachineFunction.h
U    include/llvm/CodeGen/LazyLiveness.h
U    include/llvm/CodeGen/SelectionDAGISel.h
D    include/llvm/CodeGen/MachineFunctionAnalysis.h
U    include/llvm/Function.h
U    lib/Target/CellSPU/SPUISelDAGToDAG.cpp
U    lib/Target/PowerPC/PPCISelDAGToDAG.cpp
U    lib/CodeGen/LLVMTargetMachine.cpp
U    lib/CodeGen/MachineVerifier.cpp
U    lib/CodeGen/MachineFunction.cpp
U    lib/CodeGen/PrologEpilogInserter.cpp
U    lib/CodeGen/MachineLoopInfo.cpp
U    lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
D    lib/CodeGen/MachineFunctionAnalysis.cpp
D    lib/CodeGen/MachineFunctionPass.cpp
U    lib/CodeGen/LiveVariables.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77661 91177308-0d34-0410-b5e6-96231b3b80d8

Remove this test while I figure out why it is failing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77659 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mc: Match a few X86 instructions.
 - This is "experimental" code, I am feeling my way around and working out the
   best way to do things (and learning tblgen in the process). Comments welcome,
   but keep in mind this stuff will change radically.

 - This is enough to match "subb" and friends, but not much else. The next step is to
   automatically generate the matchers for individual operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77657 91177308-0d34-0410-b5e6-96231b3b80d8