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

[Florian Mayer via llvm-commits]

fmayer wrote:

> > I don't know how many use this, and if we need some gentler way to change this behavior to avoid breaking people.
> 
> This file is relatively new. We did such change for sanitizer, no complains so far.
> 
> And it's very nuanced case ON/OFF with "emit". I see how it can be theoretically useful and good for completeness, but likely only suppression case is used to temporarily suppression.
> 
> Also I am not sure ignore/suppression list does deserve significant compatibility work. We can do that, but seems unnecessary.

I'll defer to someone who has worked on the warning suppression list.

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