tree-optimization/111891 - fix assert in vectorizable_simd_clone_call

tree-optimization/111891 - fix assert in vectorizable_simd_clone_call

The following fixes the assert in vectorizable_simd_clone_call to
assert we have a vector type during transform.  Whether we have
one during analysis depends on whether another SLP user decided
on the type of a constant/external already.  When we end up with
a mismatch in desire the updating will fail and make vectorization
fail.

	PR tree-optimization/111891
	* tree-vect-stmts.cc (vectorizable_simd_clone_call): Fix
	assert.

	* gfortran.dg/pr111891.f90: New testcase.