Method pop_back

src/script/interpreter.cpp:415–423

        ++m_stack_size;
    }
    void pop_back()
    {
        assert(m_stack_size > 0);
        --m_stack_size;
        if (m_first_false_pos == m_stack_size) {
            // When popping off the first false value, everything becomes true.
            m_first_false_pos = NO_FALSE;
        }
    }
    void toggle_top()
    {
        assert(m_stack_size > 0);