Report the openmp flag in the list of CFLAGS

configure.ac

@@ -2309,7 +2309,7 @@ AC_MSG_RESULT([
    Compiler             : $CC
     - vendor            : $ax_cv_c_compiler_vendor
     - version           : $ax_cv_c_compiler_version
-    - flags             : $CFLAGS
+    - flags             : $CFLAGS $OPENMP_CFLAGS
    MPI enabled          : $enable_mpi
    HDF5 enabled         : $with_hdf5
     - parallel          : $have_parallel_hdf5

tests/Makefile.am

@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # Add the source directory and the non-standard paths to the included library headers to CFLAGS
-AM_CFLAGS = -I$(top_srcdir)/src $(HDF5_CPPFLAGS) $(GSL_INCS) $(FFTW_INCS) $(NUMA_INCS)
+AM_CFLAGS = -I$(top_srcdir)/src $(HDF5_CPPFLAGS) $(GSL_INCS) $(FFTW_INCS) $(NUMA_INCS) $(OPENMP_CFLAGS)
 
 AM_LDFLAGS = ../src/.libs/libswiftsim.a $(HDF5_LDFLAGS) $(HDF5_LIBS) $(FFTW_LIBS) $(NUMA_LIBS) $(TCMALLOC_LIBS) $(JEMALLOC_LIBS) $(TBBMALLOC_LIBS) $(GRACKLE_LIBS) $(GSL_LIBS) $(PROFILER_LIBS)