re PR tree-optimization/70771 (ICE on valid code at -O3 on x86_64-linux-gnu in operat...

re PR tree-optimization/70771 (ICE on valid code at -O3 on x86_64-linux-gnu in operator[], at vec.h:714)

	PR tree-optimization/70771
	PR tree-optimization/70775
	* tree-if-conv.c (if_convertible_phi_p): Remove check on special
	virtual PHI nodes.  Delete parameter.
	(if_convertible_loop_p_1): Delete argument to above function.
	(predicate_all_scalar_phis): Delete code handling single-argument
	PHIs.
	(tree_if_conversion): Mark and update virtual SSA.

	gcc/testsuite/ChangeLog
	PR tree-optimization/70771
	PR tree-optimization/70775
	* gcc.dg/pr70771.c: New test.
	* gcc.dg/pr70771.c: New test.

From-SVN: r235436