re PR tree-optimization/79777 (ICE on -Os and above in on aarch64-linux-gnu (internal compiler error: in VN_INFO_GET, at tree-ssa-sccvn.c:407 }))

2017-03-02  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/79777
	* tree-ssa-pre.c (eliminate_insert): Give up if we simplify
	the to insert expression to sth existing.

	* gcc.dg/torture/pr79777.c: New testcase.

From-SVN: r245830