// for classes of conversions. For example, the first function, cvtInt,
// takes any value v of signed int type and returns the value converted
// to type t, where t is any signed or unsigned int type.

// convertOp: intXX -> [u]intXX
func cvtInt(v Value, t Type) Value {
	return makeInt(v.flag.ro(), uint64(v.Int()), t)
}

// convertOp: uintXX -> [u]intXX
func cvtUint(v Value, t Type) Value {