* omp-low.c (check_omp_nesting_restrictions): New function.
	(scan_omp_1): Call it.

	* gcc.dg/gomp/critical-4.c: New test.
	* gcc.dg/gomp/appendix-a/a.35.1.c: Add dg-warning.
	* gcc.dg/gomp/appendix-a/a.35.3.c: Likewise.
	* gfortran.dg/gomp/appendix-a/a.35.1.f90: Likewise.
	* gfortran.dg/gomp/appendix-a/a.35.3.f90: Likewise.

From-SVN: r113790