Fortran - Improve OpenMP/OpenACC diagnostic

Fortran - Improve OpenMP/OpenACC diagnostic

	gcc/fortran/
	* match.h (gfc_match_omp_eos_error): Renamed from gfc_match_omp_eos.
	* openmp.c (gfc_match_omp_eos): Make static.
	(gfc_match_omp_eos_error): New.
	* parse.c (matchs, matchdo, matchds): Do as done for 'matcho' -
        if error occurred after OpenMP/OpenACC directive matched, do not
	try other directives.
	(decode_oacc_directive, decode_omp_directive): Call new function
	instead.

	testsuite/
	* gfortran.dg/goacc/continuation-free-form.f95: Update dg-error.

From-SVN: r276694