[Bug c++/123087] logical negation of a nullptr incorrectly errors according to [expr.unary.op] paragraph 9

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123087

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
https://cplusplus.github.io/CWG/issues/1781.html