re PR rtl-optimization/58726 (wrong code at -Os on x86_64-linux-gnu (affecting trunk/4.7/4.6, but not 4.8))

	PR rtl-optimization/58726
	* combine.c (force_to_mode): Fix comment typo.  Don't destructively
	modify x for ROTATE, ROTATERT and IF_THEN_ELSE.

	* gcc.c-torture/execute/pr58726.c: New test.

From-SVN: r205664