Convert Array.IsPrimitiveTypeArray to C# - #27302

Does this change make any measurable performance difference?

If we start duplicating the VM code in C# just because we can, it will tun into maintenance nightmare. For now, I would prefer to keep this duplication at minimum and do as needed only if there is a measurable benefit.

I don't know to to set g_pEnumClass global in order to test

I do not think we want to keep these in a global. Ideally, This should just be typeof(Enum).MethodTable or something like that. It is what we do in CoreRT.

#if FEATURE_PREJIT parts

Yep, these would need to be much more complex, otherwise this will break Samsung folks who stilll use fragile NGen.

@jkotas ok, makes sense, will wait for CI test results just to make sure it works
PS: Also, could re-use this code for Enum.InternalGetCorElementType internal call.
But yeah don't want to break anyone or increase maintenance costs.