PR fortran/77500
	* trans-openmp.c (gfc_trans_omp_atomic): For atomic write or
	swap, don't try to look through GFC_ISYM_CONVERSION.  In other cases,
	check that value.function.isym is non-NULL before dereferencing it.

	* gfortran.dg/gomp/pr77500.f90: New test.

From-SVN: r240038