[PATCH] [PR rtl-optimization/49847] Fix ICE in CSE due to cc0-setter and cc0-user in different blocks

	PR rtl-optimization/49847
	* cse.c (record_jump_equiv): Handle fold_rtx returning NULL_RTX.

	PR rtl-optimization/49847
	* g++.dg/pr49847-2.C: New test.

From-SVN: r231821