[llvm] [MergeFunctions] Preserve instruction-level profile metadata during merging (PR #208009)

[Alok Kumar Sharma via llvm-commits]

alokkrsharma wrote:

> BTW - I think I managed to delete my comment on this (or it never made it through - because I remember writing it, but that was when we had the github fluke when a bunch of messages got replicated a bunch of times, and then I went and deleted them); anyway, if there's interest in MergeFunctionsPass, you'd probably want to remove [its exclusion from profcheck](https://github.com/llvm/llvm-project/blob/18d2b47a0d3b6bb5d55260e69bf51c47de8e0dc6/llvm/test/lit.cfg.py#L83). Then, if there are failing tests, I'd suggest adding them to llvm/utils/profcheck-xfail.txt first, then removing them from there as fixes make it in.

Thanks, that's helpful. I'd be happy to look into removing the profcheck exclusion in a separate PR and triaging any resulting failures via profcheck-xfail.txt.

https://github.com/llvm/llvm-project/pull/208009