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.

struct V(T...) {
    T v;
}

alias V!(float, int) MyV;

void main()
{
    assert(MyV.sizeof == float.sizeof + int.sizeof);
    auto f = 3.75f;
    auto v = MyV(f, 3);
    assert(v.v[0] == 3.75f);
    assert(v.v[1] == 3);
}