[sledge] Enable LLVM transformations on test code compiled with -O0
[sledge] Enable LLVM transformations on test code compiled with -O0

Summary:
By default compiling with `-O0` adds `optnone` annotations, which
prevents the transformations sledge explicitly performs. This diff
adds a flag to disable this uncooperative behavior.

Reviewed By: ngorogiannis

Differential Revision: D27564879

fbshipit-source-id: 061397e3f

facebook/infer,jvillard/infer,facebook/infer,facebook/infer,facebook/infer,jvillard/infer,facebook/infer,jvillard/infer,jvillard/infer,facebook/infer,facebook/infer,jvillard/infer,jvillard/infer,jvillard/infer