Hi,

The current codegen code to support VF's that are multiples of a 
simdclone simdlen rely on BIT_FIELD_REF to create multiple input 
vectors.  This does not work for non-constant simdclones, so we should 
disable using such clones when
the VF is a multiple of the non-constant simdlen until we change the 
codegen to support those.

Enabling SVE simdclone support will cause ICEs if the vectorizer decides 
to use a SVE simdclone with a VF that is larger than the simdlen. I'll 
be away for the next two weeks, so cant' really discuss this further.
I initially tried to solve the problem, but the way 
vectorizable_simd_clone_call is structured doesn't make it easy to 
replace BIT_FIELD_REF with the poly-suitable solution right now of using 
unpack_{hi,lo}. Unfortunately I only found this now as I was adding 
further tests for SVE :(

gcc/ChangeLog:

	* tree-vect-stmts.cc (vectorizable_simd_clone_call): Reject simdclones
	with non-constant simdlen when VF is not exactly the same.