[clang] [Clang][Driver][SamplePGO] Enable -fsample-profile-use-profi for SamplePGO (PR #145957)

[Snehasish Kumar via cfe-commits]

snehasish wrote:

We evaluated profi internally (at Google) last year. Our configuration uses AutoFDO with [flow-sensitive discriminators ](https://lists.llvm.org/pipermail/llvm-dev/2020-November/146694.html) (FS-AFDO). We found slight regressions with this configuration and didn't enable it for our workloads. With FS-AFDO we see performance improvements of ~1%. Can you share your configuration and performance numbers? 




https://github.com/llvm/llvm-project/pull/145957