[PATCH] [lld] Boot bitrotting add_lld_library() from CMake build

[Rafael Espíndola]

> 2. This is highlighting a problem with add_llvm_library that I should have spotted before asking you to use it. Sorry for that. Namely, I don't think it makes sense to have 'LLVMlldConfig' as a library name, and that'll be the result of this approach as far as I understand it.

Note that llvm_add_library is used in clang (from add_clang_library),
so I think the names are handled correctly.

Cheers,
Rafael