[llvm] [RISCV] Fold `addi` into load / store even if they are in different BBs. (PR #67024)

[Craig Topper via llvm-commits]

topperc wrote:

> Also, some many things are easier to implement while we are still in SSA.

We're still in SSA form where MergeBaseOffset is now. So I don't understand this statement.

https://github.com/llvm/llvm-project/pull/67024