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 tangotests.switch3;

void main()
{
    int i = 2;

    switch(i)
    {
        case 0,1,4,5,6,7,8,9:
            assert(0);
        case 2:
            return;
        case 3:
        {
            i++;
            case 11:
                i++;
        }
        return;
    }
}