`offset_of` doesn't correctly calculate offsets of members from nested structs

[avanspector]

R1 :: struct {
	_: u16,
	_: int,
	i: int,
}

R2 :: struct {
	_: u16,
	r: R1,
	_: int,
}

main :: proc() {
	r2: R2

	fmt.println(offset_of(R2{}.r.i)) // 16, wrongly assumes offset_of(R1, i)

	fmt.println(offset_of(R2, r) + offset_of(R1, i)) // 24, right

	fmt.println(uintptr(&r2.r.i) - uintptr(&r2)) // // 24, right
}

A fix could imply viability of the offset_of(R2, r.i)/offset_of(R2, "r.i") feature as well.