re PR fortran/77374 (ICE in resolve_omp_atomic, at fortran/openmp.c:3949)

re PR fortran/77374 (ICE in resolve_omp_atomic, at fortran/openmp.c:3949)

	PR fortran/77374
	* parse.c (parse_omp_oacc_atomic): Copy over cp->ext.omp_atomic
	to cp->block->ext.omp_atomic.
	* resolve.c (gfc_resolve_blocks): Assert block with one or two
	EXEC_ASSIGNs for EXEC_*_ATOMIC.
	* openmp.c (resolve_omp_atomic): Don't assert one or two
	EXEC_ASSIGNs, instead return quietly for EXEC_NOPs and otherwise
	error unexpected statements.

	* gfortran.dg/gomp/pr77374.f08: New test.

From-SVN: r239903