[Bug libstdc++/71579] type_traits miss checks for type completeness in some traits

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71579
Bug 71579 depends on bug 109997, which changed state.

Bug 109997 Summary: __is_assignable(int, IncompleteType) should be rejected
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109997

           What    |Removed                     |Added
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             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED