Add Function Pointer support to Native AOT Reflection 

Once https://github.com/dotnet/runtime/issues/69273 is in for CoreClr, Native AOT should uptake that. It is expected that the CoreClr implementation will be for V7.

See also https://github.com/dotnet/runtime/issues/71095 for Mono.