[Bug fortran/82968] gfortran.dg/ieee/ieee_6.f90 fails at -O0

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82968

--- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
I get this compilation error:

In file included from /home/ebotcazou/src/libgfortran/runtime/fpu.c:29:
./fpu-target.h:36:24: error: invalid application of 'sizeof' to incomplete type
'struct fenv'
   36 | _Static_assert (sizeof(struct fenv) <= 8 * GFC_FPE_STATE_INT_KIND,
      |                        ^~~~~~
./fpu-target.h:36:17: error: expression in static assertion is not an integer
   36 | _Static_assert (sizeof(struct fenv) <= 8 * GFC_FPE_STATE_INT_KIND,
      |                 ^~~~~~
make[2]: *** [Makefile:3071: fpu.lo] Error 1
make[2]: Leaving directory
'/home/ebotcazou/build/sparc64-linux-gnu/libgfortran'
make[1]: *** [Makefile:1692: all] Error 2
make[1]: Leaving directory
'/home/ebotcazou/build/sparc64-linux-gnu/libgfortran'
make: *** [Makefile:23173: all-target-libgfortran] Error 2