[Bug c++/86441] instantiate_class_template() unable to re-execute constexpr function

[boris at kolpackov dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86441

--- Comment #1 from Boris Kolpackov <boris at kolpackov dot net> ---
Created attachment 44366
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44366&action=edit
Test case that shows the problem if compiled with ODB

For the record, a test case that triggers the error if compiled with ODB that
uses GCC 8.