X86: Register the X86CallFrameOptimization pass

Summary:
The motivation of this change is to enable .mir testing for this pass.
Added one test case to cover the functionality, this same case will be improved by
a future patch.

Reviewers: igorb, guyblank, DavidKreitzer

Reviewed By: guyblank, DavidKreitzer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38729

llvm-svn: 316412