PR tree-optimization/92401
	* gimple-match-head.c (gimple_resimplify1): Call const_unop only
	if res_op->code is an expression with code length 1.
	* gimple-match-head.c (gimple_resimplify2): Call const_binop only
	if res_op->code is an expression with code length 2.
	* gimple-match-head.c (gimple_resimplify3): Call fold_ternary only
	if res_op->code is an expression with code length 3.

	* g++.dg/opt/pr92401.C: New test.

From-SVN: r278004