Adding the ?. null verification

[Etienne via Digitalmars-d]

> I want non-null in the type system! To put a nullable reference into a
> non-null variable you need to check first, but from then on the compiler
> can ensure it's never null!

That would be great but useless for my situation involving some complex 
AST's

class AEntity
{
	Module head;
	string ident;
	Type type;
	AEntity typeInfo;
	AEntity[] members; // for definitions
	AEntity[] parameters; // if parameterized
...
}

It's very useful to descend through parts of a complex tree without 
adding plenty of bool checks

foreach (AEntity member; entity.members)
{
	if (member.typeInfo !is null)
	{
		AEntity curr = member;
		member.ident ~= member.typeInfo.ident;
		curr = member.typeInfo;
		while (curr.typeInfo !is null)
		{
			member.ident ~= "." ~ curr.typeInfo.ident;
			curr = curr.typeInfo;
		}
	}
}