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 bar {
    int bar;
}

void main() {
    bar Bar;
    with (Bar)
    {
        assert(Bar.bar == 0);
        void test()
        {
            bar ++;
        }
        test();
    }
    assert(Bar.bar == 1);
}