[llvm] [RISCV] Ensure LPAD alignment for calls to returns_twice functions (PR #177515)

[Sam Elliott via llvm-commits]

lenary wrote:

Sorry for not getting back to this, I was not on top of my inbox, then I was away. I am happy with the current implementation, but would like you to follow-up with support for `call.lpad`/`jalr.lpad` pseudos

https://github.com/llvm/llvm-project/pull/177515