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 structs3;

struct S
{
    char c;
    float f;
}

struct T
{
    S s;
    long l;
}

void main()
{
    T t;
    float f = void;
    float* fp = void;
    {f = t.s.f;}
    {t.s.f = 0.0;}
    {fp = &t.s.f;}
    {*fp = 1.0;}
    {assert(t.s.f == 1.0);}
    {assert(*(&t.s.f) == 1.0);}
    {t.s.c = 'a';}
    {assert(t.s.c == 'a');}
    {t.l = 64;}
    {assert(t.l == 64);}
}