[lld] [lld][ELF] Support relax R_LARCH_{ALIGN, PCALA_{HI20,LO12}, GOT_PC_{HI20,LO12}} (PR #78692)

[Fangrui Song via llvm-commits]

MaskRay wrote:

For release/18.x, I think relaxing just `R_*_ALIGN` is safer. We need more time to think about GOT relaxation. Relaxing once may not converge when other features like RELR are involved. Can you split the patch?

https://github.com/llvm/llvm-project/pull/78692