c-parser.c (c_parser_omp_clause_schedule): Warn if OMP_CLAUSE_SCHEDULE_CHUNK_EXPR is known not to be positive.

	* c-parser.c (c_parser_omp_clause_schedule): Warn if
	OMP_CLAUSE_SCHEDULE_CHUNK_EXPR is known not to be positive.

	* semantics.c (finish_omp_clauses) <case OMP_CLAUSE_SCHEDULE>: Warn
	if OMP_CLAUSE_SCHEDULE_CHUNK_EXPR is known not to be positive.

	* openmp.c (resolve_omp_clauses): Warn if chunk_size is known not to
	be positive.

	* c-c++-common/gomp/schedule-1.c: New test.
	* gfortran.dg/gomp/schedule-1.f90: New test.

	* testsuite/libgomp.c/doacross-1.c (main): Use schedule(static)
	instead of invalid schedule(static, 0).
	* testsuite/libgomp.c/doacross-2.c (main): Likewise.

From-SVN: r236793