re PR tree-optimization/23445 (ICE with -O1 -ftree-vrp -fdelete-null-pointer-checks)

	PR 23445
	* tree-vrp.c (extract_range_from_assert): If the new numeric
	range created out of the assertion contradicts the existing
	numeric range of the ASSERT_EXPR variable, make the new range
	varying.

testsuite/
	PR 23445
	* gcc.c-torture/compile/pr23445.c: New test.

From-SVN: r104936