[dsymutil] Add the DwarfStreamer class.

[dsymutil] Add the DwarfStreamer class.

This class is responsible for getting the linked data to the
disk in the appropriate form. Today it it an empty shell that
just instantiates an MC layer.

As we do not put anything in the resulting file yet, we just
check it has the right architecture (and check that -o does
the right thing).

To be able to create all the components, this commit adds a
few dependencies to llvm-dsymutil, namely all-targets, MC and
AsmPrinter.

Also add a -no-output option, so that tests that do not need
the binary result can continue to run even if they do not have
the required target linked in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230824 91177308-0d34-0410-b5e6-96231b3b80d8