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

[Mingming Liu via llvm-commits]

mingmingl-llvm wrote:

Thanks for sharing the thoughts folks!

> I believe the intention of --default-script is to be used by e.g. toolchain configs, so that users can override the script if they have one of their own. 

Exactly. This matches how `--default-script` is used on the motivating use cases.

> A lint could be added to a linker wrapper to report the warning, but this functionality should not be part of LLD itself.

This is not unreasonable. I'll close this patch then.

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