[Bug c++/116071] [14/15 Regression] Non-inline destructor for class template rejected with -std=gnu++14 -fconcepts

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116071

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
N.B. not a high priority regression, because -std=gnu++14 -fconcepts is not
important to support (and the library headers are completely unusable with
those flags, even without this regression).