[PATCH] D42823: Strip .note.gnu.build-id sections if --build-id is given.

[Rafael Avila de Espindola via llvm-commits]

LGTM with a nit:
> Index: lld/ELF/InputFiles.cpp
> ===================================================================
> --- lld/ELF/InputFiles.cpp
> +++ lld/ELF/InputFiles.cpp
> @@ -618,6 +618,13 @@
>    if (Name.startswith(".gnu.linkonce."))
>      return &InputSection::Discarded;
>  
> +  // If we are creating a new .build-id section, strip existing .build-id
> +  // sections so that the output won't have more than one .build-id.
> +  // Usually, input object files don't contain .build-id sections, but if you
> +  // create them with "ld -r --build-id", they contain it.
> +  if (Name == ".note.gnu.build-id" && Config->BuildId != BuildIdKind::None)
> +    return &InputSection::Discarded;

Mention that both bfd and gold also create a .note.gnu.build-id section
with -r -build-id.

Cheers,
Rafael