[lldb] [llvm] [lldb][Process/FreeBSD] Add riscv64 support (PR #180549)

[David Spickett via llvm-commits]

DavidSpickett wrote:

I looked at x86. RegisterContext_x86.h defines a bunch of stuff, for example a type to represent some special register kinds. This is then included in RegisterContextPOSIX_x86.h and RegisterContextWindows_x86_64.cpp.

This is not the case for RISCV where RegisterContextDarwin_riscv32.h and RegisterContextPOSIX_riscv32.h seem to do their own thing.

I'd get it working and then go looking for overlaps between them all. It might be small enough that it's not worth a refactor.

https://github.com/llvm/llvm-project/pull/180549