`GetRegisterInfo` hardcodes to use `RegisterInfoPOSIX_riscv64` instead of checking the triple to determine whether to use `RegisterInfoPOSIX_riscv64` or `RegisterInfoPOSIX_riscv32`. Someone put up a [PR](https://github.com/llvm/llvm-project/pull/175262) for this, but seems to have removed their account and the associated PR with it. Fixes #175092