[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
- 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