`-u` is a linker option used to pretend a symbol is undefined,
this option are common used for forcing archive member extraction.
This option should pass to `ld`, and many other toolchain in Clang
like `tools::gnutools` has pass that too.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D105091
In baremetal::Linker::ConstructJob, LinkerInput is handled prior to T_Group options,
but on the other side in RISCV::Linker::ConstructJob, it is opposite.
We want it to be consistent whether users are using RISCV::Linker or baremetal::Linker.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D100615
Kito Cheng