[Bug c++/94554] spurious -Waddress warning within "if constexpr" function-null compares

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94554

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Daniel Krügler from comment #3)
> The example is ill-formed because the condition of 'if constexpr' is more
> restricted than that of normal 'if': It expects "a contextually converted
> constant expression of type bool" and [expr.const] p10 lists the allowed
> conversions in this case. This list omits the boolean conversions
> ([conv.bool]).

This was changed by wg21.link/p1401 so the conversion is allowed in this
context as well.