[Bug c++/91369] Implement P0784R7: constexpr new

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91369

--- Comment #27 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 47590
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47590&action=edit
gcc10-pr91369-2.patch

Untested patch.