[llvm] [RISCV] Fix musttail with indirect arguments by forwarding incoming pointers (PR #185094)

[Xavier Roche via llvm-commits]

xroche wrote:

> cc @heiher you probably want to update the loongarch backend in a similar way.

It seems to have the same non-musttail bug at LoongArchISelLowering.cpp:8427-8428 (unconditionally rejecting tail calls when any arg is indirect, with no musttail exception at all)

I could do a follow-up fix for loongarch, but considering I missed the swapped-args case, this might suggest there may be other subtle scenarios I missed...

https://github.com/llvm/llvm-project/pull/185094