[llvm-branch-commits] [clang] Clang multi-match behavior of WarningSuppressionMappings (PR #162237)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/162237

"The longest wins" is confusing.
E.g. why here `test/` should win?

```
src:*test/*
src:*lld/*=emit
```

For long suppression files length relationship can be hard to track.

Easier to understand rule is "the last wins".

We changed sanitizers to this approach way and
would be nice to have consistency hare.

Also consistency allows us avoid exposing
internals of SpecialCaseList in future.