[clang] [clang] Updating to include gcc-toolsets 13 and 14 (PR #128438)

[Fangrui Song via cfe-commits]

MaskRay wrote:

I think redhat gcc-toolset support should move to Clang configuration files https://reviews.llvm.org/D136435 @tbaederr 

https://github.com/llvm/llvm-project/pull/128438