[X86] Fix llc invocation on MIR test case

The current state of the llc invocation is:

* Running all the passes from dwarfehprepare to stack coloring
(included)
* It runs it from the LLVM IR included in the file
* It *ADDS* the generated MI from ISel to the MI in the MIR file
* The machine verifier doesn't like it.

Differential Revision: https://reviews.llvm.org/D53698

llvm-svn: 345266