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 scope_exit_foreach;

void bar(size_t);

long foo(ubyte[] arr) {
    scope(exit) {
        foreach (ref b; arr) {
            bar(b);
        }
    }
    if (arr.length == 3)
        return 0;
    return arr.length;
}