[lld] [llvm] [RISCV] Teach RISCVMergeBaseOffset to merge %lo into load/store folding arithmetic (PR #185353)

[Pengcheng Wang via llvm-commits]

wangpc-pp wrote:

I don't really get the usage scenarios of these new relocations, I think we should discuss this in psabi first. 

https://github.com/llvm/llvm-project/pull/185353