Test case 1:

-----------------------------
auto bug6430(int a) {
    static struct Result2 {}
    return 4;
}
auto bug6430(int a, int b) {
    static struct Result2 {
        int z;
        int y() { return z; }   // <-- line 11
    }
    auto t = Result2(1);   // <-- line 13
    return 5;
}
-----------------------------
x.d(11): Error: this for z needs to be type Result2 not type Result2
x.d(13): Error: more initializers than fields of Result2
-----------------------------

The same happens if we replace 'static struct' as 'class' or 'union' with or without 'static'.