Function pop_two 

pub unsafe fn pop_two(
    stack: *mut StackValue,
    _op_name: &str,
) -> (*mut StackValue, Value, Value)

Pop two values from the stack (for binary operations)

Returns (new_sp, a, b) where a was below b on stack. Stack effect: ( a b – ) returns (a, b)

Safety

Stack must have at least two values.