[lld] [wip][LLD] Support RISCV vendor-specific relocations. (PR #168497)

[Sam Elliott via llvm-commits]

https://github.com/lenary commented:

I like the iterator, it seems clean and a sensible wrapper for the logic.

I have more feedback about the bitfields, at the moment, but overall I'm happy with the direction so far.

I haven't yet had to think about dynamic relocations, and if they have some differences compared to the existing design/spec (are local symbols a problem here?)

https://github.com/llvm/llvm-project/pull/168497