[Bug libstdc++/86398] [8/9 Regression] is_trivially_constructible always returns true even when is_constructible returns false

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86398

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-07-04
          Component|c++                         |libstdc++
      Known to work|                            |7.3.0
   Target Milestone|---                         |8.2
            Summary|is_trivially_constructible  |[8/9 Regression]
                   |always returns true even    |is_trivially_constructible
                   |when is_constructible       |always returns true even
                   |returns false               |when is_constructible
                   |                            |returns false
     Ever confirmed|0                           |1
      Known to fail|                            |8.1.0, 9.0

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Presumably started with r248153