[Bug c++/77832] isnan() check causes signal 8 with signaling nans

[gmc at synopsys dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77832

--- Comment #1 from Gordon Mc <gmc at synopsys dot com> ---
Created attachment 39742
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39742&action=edit
Makefile