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

[via llvm-commits]

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+; REQUIRES: x86_64-linux
+; RUN: not opt < %S/pseudo-probe-profile-mismatch.ll -passes=sample-profile -sample-profile-file=%S/Inputs/pseudo-probe-profile-mismatch.prof  -min-functions-for-staleness-error=1  -precent-mismatch-for-staleness-error=1 -S 2>&1 | FileCheck %s
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WenleiHe wrote:

add a negative test for now showing the error when not meeting the thresholds (of % mismatched functions or min functions)? 

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