tree-optimization/112505 - bit-precision induction vectorization

Vectorization of bit-precision inductions isn't implemented but we
don't check this, instead we ICE during transform.

	PR tree-optimization/112505
	* tree-vect-loop.cc (vectorizable_induction): Reject
	bit-precision induction.

	* gcc.dg/vect/pr112505.c: New testcase.