[compiler-rt] [llvm] [clang] [clang-tools-extra] Bfi precision (PR #66285)

[David Li via cfe-commits]

david-xl wrote:

@MatzeB ,Our internal release testing have seen lots of very large regressions for tests without PGO or with XFDO only. While I agree this patch is the right way to go and the good performance (without PGO) with oldBFI is somewhat by chance, it is still better not to regress them. Can you help with a follow up patch to tune down relative coldness threshold?

https://github.com/llvm/llvm-project/pull/66285