Make == for associative arrays test for equality, not identity. _aaEq was added to runtime/internal/aaA.d which forwards to TypeInfo_AssociativeArray.equals in genobj.d. On the codegen side, DtoAAEquals was added to gen/aa.cpp and is called from EqualExp::toElem in gen/toir.cpp. I assume that the frontend will produce an error if == is used on associative arrays of different type. This fixes DMD bug 1429.

module classes5;
extern(C) int printf(char*, ...);

struct S
{
    long l;
}

class C
{
    C c;
    S s;
}

void main()
{
    C c = new C;
    long* lp = void;
    {c.s.l = 64;}
    {assert(c.s.l == 64);}
    {lp = &c.s.l;}
    {assert(*lp == 64);}
    printf("classes5 success\n");
}