[lld] [lld][ELF] Add basic TLSDESC support for LoongArch (PR #94451)

[Fangrui Song via llvm-commits]

https://github.com/MaskRay commented:

The code change looks good. Do you have plan for TLSDESC to LE/IE optimization?

https://github.com/llvm/llvm-project/pull/94451