[clang] [clang] recognize hexagon-*-ld.lld variants (PR #117338)

[Brian Cain via cfe-commits]

androm3da wrote:

> I am still not sure about this change.
> 
> I think this common utility is only to make `-fuse-ld=lld` recognize LinkerIsLLD. Toolchains/Hexagon.cpp detects ld.lld and you can make the change there?

Okay - the scope is now reduced to `Toolchains/Hexagon.cpp` only.

https://github.com/llvm/llvm-project/pull/117338