* tree-vrp.c (check_array_ref): Emit more warnings
	for warn_array_bounds >= 2.
	* common.opt: New option -Warray-bounds=.
	* doc/invoke.texi: Document -Warray-bounds=.

	* c.opt: New option -Warray-bounds=.

	* gcc.dg/Warray-bounds-11.c: New test-case.

From-SVN: r219577