Adding the ?. operator to D

[Per Nordlöw]

Has there been any discussions on adding the ?. operator to 
simplify structure matching on class trees typically found in 
compilers such as dmd.

Basically, implemented via lowering of

     C ?. EXPR

to

     C ? C.EXPR : EXPR.init

when EXPR has type class or pointer and for the other cases either

     C ? C.EXPR : EXPR.init

or perhaps even

     C ? C.EXPR : nullable(EXPR).init

if nullable is made part of the runtime or even builtin.

Given that `C` is a class or pointer to an aggregate.

C# supports has this [1].

[1] 
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/member-access-operators#null-conditional-operators--and-