Fixed a nasty bug with how interface vtables for class initializers were output, causing some class fields to be skipped. Fixed a problem in definition of ClassInfos where an invalid constant was potentially used. This needs to be looked into proper as it might happen again in the future.

struct Foo { int a, b, c; union Data { } Data data; }
struct Bar { int a, b; }
struct Baz { int a; union { Foo foo; Bar bar; } }
void test() { Baz baz; if (baz.bar.a) return; }