Implement a Q_ASSERT2(cond, what) macro possibly defined as Q_ASSERT_X(cond, Q_FUNC_INFO, what)

I often write an explanation for an assertion, but never pass anything other than Q_FUNC_INFO as the where parameter to Q_ASSERT_X. Q_FUNC_INFO is passed to Q_ASSERT_X in 40 places in qtbase. Using Q_ASSERT2 would be more concise and less error-prone.