Clean up some suspicious code. There's no guarantee a constant of integer type is a ConstantInt, so it's not safe to just cast<> these to ConstantInt. (It could be a constant expression, for example) The code is shorter this way too :).

module bug52;
struct Vec { double x,y,z; }
struct Pair(T, U) { T first; U second; }
typedef Pair!(double, Vec) Hit;
void main() {}