Invert the MC -> Object dependency.

Now that we have a lib/MC/MCAnalysis, the dependency was there just because
of two helper classes. Move the two over to MC.

This will allow IRObjectFile to parse inline assembly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212248 91177308-0d34-0410-b5e6-96231b3b80d8