re PR middle-end/70992 (Infinite recursion between fold_build2_stat_loc and fold_binary_loc w/ -fwrapv)

	PR middle-end/70992
	* tree.c (build2_stat): Don't set TREE_CONSTANT on divisions by zero.

	* gcc.dg/overflow-warn-1.c: Adjust dg-error.
	* gcc.dg/overflow-warn-2.c: Likewise.
	* gcc.dg/overflow-warn-3.c: Likewise.
	* gcc.dg/overflow-warn-4.c: Likewise.
	* gcc.dg/torture/pr70992-2.c: New test.
	* gcc.dg/torture/pr70992.c: New test.

From-SVN: r250566