[Mercury Feature request] Make it possible to call ref overloaded C# methods

In C# you can write the following:

public void test(ref String a, string b) { a = b}
public void test(String a, out string b) { b = a}

So, 2 methods with exactly the same signature that are overloaded on ref.
This is not possible in VB, and I think it is best to keep it that way.
But we want to be able to call all C# methods.

Therefore I’d like to add the ByRef, In and Out keywords to the calling parameters.
Optional for normal situations, but mandatory when there is a ref, in or out overload.

Syntax:

test(ByRef a, b) 'call the first overload
test(a, out b) 'call the second overload