re PR tree-optimization/66142 (Loop is not vectorized because not sufficient support for GOMP_SIMD_LANE)

	PR tree-optimization/66142
	* tree-if-conv.c (if_convertible_phi_p): Don't give up on
	virtual phis that feed themselves.

	* gcc.dg/vect/pr66142.c: New test.

From-SVN: r223863