[Bug fortran/68744] FAIL: gfortran.dg/backtrace_1.f90 -O0 execution test

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68744

--- Comment #7 from John David Anglin <danglin at gcc dot gnu.org> ---
Created attachment 37012
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37012&action=edit
Patch

I don't expect this to work but it points at the problem.  The call to
backtrace_create_state() assumes threaded code.  backtrace_create_state()
returns NULL if HAVE_SYNC_FUNCTIONS is not defined.