Bug case to gather issues related to type propagation of internal associative arrays to instances of AssociativeArray!(Key, Value).
Type properties are erroneously taken from the template instance.
.init, .stringof, .mangleof, .offsetof, .alignof
issue 3962, issue 5683, issue 5029
AssocArrayLiteralExp can't handle type propagation.
issue 5675
Deprecated "delete aa[key]" segfaults on x86_64.