Use Evan's outflag stuff to implement V8cmpicc. This allows us to write a

Use Evan's outflag stuff to implement V8cmpicc.  This allows us to write a
pattern for SUBCCrr, and makes it trivial to add support for SUBCCri, eliminating
an instruction in the common "setcc X, imm" case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25212 91177308-0d34-0410-b5e6-96231b3b80d8