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

[Bill Blum via cfe-commits]

roadswitcher wrote:

| I suspect that this change may be about people building their own clang (not the one RHEL ships) and wanting to use GCC toolset.

Sorry, I should have been more specific in my original comment.
Yes, we are building LLVM 19 from source along with a number of other tools/libraries and are trying to standardize on using the most recent gcc-toolset available to us in the process.  

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