[lld] [lld][ELF][X86] Add missing X86_64_TPOFF64 case in switches (PR #77208)

[Fangrui Song via llvm-commits]

MaskRay wrote:

Thanks for the update.

> Actually, it's LLVM/clang. I have submitted a concurrent patch for allowing LLVM to emit R_X86_64_TPOFF64 relocations, which a project I'm working on requires.

This is interesting. R_X86_64_TPOFF32 supports offsets up to -2**31, which is much more than sufficient.
Extremely large TLS offsets likely do not work on many libc/rtld implementations.

https://github.com/llvm/llvm-project/pull/77208