[clang] [lld] [llvm] [X86, lld] Add relocation R_X86_64_REX2_GOTPCRELX (PR #106681)

[Shengchen Kan via cfe-commits]

KanRobert wrote:

TODO: 
* [ ] Pass tests lld/test/ELF/x86-64-gotpc-relax.s and lld/test/ELF/x86-64-gotpc-relax-nopic.s

https://github.com/llvm/llvm-project/pull/106681