[compiler-rt] [compiler-rt][RISC-V] Save-Restore for ILP32E/LP64E ABIs (PR #95390)

[Jessica Clarke via llvm-commits]

https://github.com/jrtc27 requested changes to this pull request.

libgcc is as our compiler-rt is today. Switching to look at the ABI not the ISA makes sense to me, and sounds like an oversight in GCC that got mirrored to LLVM (after all, it's an unusual combination to use), but we need to match GCC's ABI for RVE save/restore libcalls, which is to always save all three registers.

https://github.com/llvm/llvm-project/pull/95390