[llvm-branch-commits] [lld] [llvm] [RISCV] Support RISC-V TLSDESC in LLD (PR #77516)

[Paul Kirth via llvm-branch-commits]

https://github.com/ilovepi created https://github.com/llvm/llvm-project/pull/77516

This patch adds support for RISC-V TLSDESC relocations, as described in
https://github.com/riscv-non-isa/riscv-elf-psabi-doc/pull/373.

It does not attempt to handle relaxation for these cases, which will be
handled separately.