[clang] [llvm] [RISCV] CodeGen of RVE and ilp32e/lp64e ABIs (PR #76777)

[Nemanja Ivanovic via cfe-commits]

https://github.com/nemanjai approved this pull request.

My comments have been addressed, so this LGTM. I'll of course defer to @asb and @topperc for final approval.

https://github.com/llvm/llvm-project/pull/76777