Moving UniqueInternalLinkageNamesPass to the start of IR pipelines.

`UniqueInternalLinkageNamesPass` is useful to CSSPGO, especially when pseudo probe is used. It solves naming conflict for static functions which otherwise will share a merged profile and likely have a profile quality issue with mismatched CFG checksums. Since the pseudo probe instrumentation happens very early in the pipeline, I'm moving `UniqueInternalLinkageNamesPass` right before it. This is being done only to the new pass manager.

Reviewed By: dblaikie, aeubanks

Differential Revision: https://reviews.llvm.org/D93656