[llvm] [CSSPGO] Error out if the checksum mismatch is high (PR #84097)

[Lei Wang via llvm-commits]

wlei-llvm wrote:

> The current version looks good. For testing, have you tried to build with some workloads to make sure we don't have false positives?

Yeah, I'm going to give another tuning for this "HotFuncCutoffForStalenessError" flag value.

https://github.com/llvm/llvm-project/pull/84097