[lld] [lld][ELF]Emit warning when both scripts are specified (PR #163497)

[Fangrui Song via llvm-commits]

https://github.com/MaskRay requested changes to this pull request.

I agree with lenary's analysis. The design intent of --default-script is to allow it to be overridden by linker scripts without generating a warning (or an error if --fatal-warnings is used). A lint could be added to a linker wrapper to report the warning, but this functionality should not be part of LLD itself.

https://github.com/llvm/llvm-project/pull/163497