[Bug c++/115645] [11/12/13/14/15 Regression] new S[1][1]() requires non-explicit default ctor since r11-3092

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115645

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(although an explicit default ctor is unusual, so it's not going to really
affect anybody in practice)