Make type comparisons more general purpose (#20940)

Make type comparisons more general purpose (#20940)

This has two parts:

## Part 1
CoreRT represents native type handles differently from CoreCLR - on CoreCLR, `RuntimeTypeHandle` is a wrapper over `RuntimeType` and RyuJIT is aware of that. On CoreRT, `RuntimeTypeHandle` wraps the native type handle, not a `RuntimeType`.

The knowledge is hardcoded in importer when importing the sequence "ldtoken foo / call Type.GetTypeFromHandle" - importer just removes the call and bashes the result of ldtoken to be a reference type. CoreRT had to avoid reporting `Type.GetTypeFromHandle` as an intrinsic because of that.

I'm adding another helper that lets RyuJIT avoid hardcoding that knowledge. Instead of just bashing the return type, we swap the helper call.

## Part 2

Native type handle equality checks need to go through a helper, unless the EE side says it's okay to compare native type handles directly.