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 scope5;

int i;

void func(int a, int b)
{
    i = 0;
    {
        scope(exit) i++;
        if (a) {
            scope(exit) i++;
            if (b) return;
            i++;
        }
    }
    i++;
}

void main()
{
    func(0,0);
    assert(i == 2);
    func(1,1);
    assert(i == 2);
    func(1,0);
    assert(i == 4);
}