Remove last gimple_expr_type uses

Remove last gimple_expr_type uses

This removes the last uses of gimple_expr_type.

2021-07-16  Richard Biener  <rguenther@suse.de>

	* tree-ssa-sccvn.c (vn_reference_eq): Handle NULL vr->type.
	(ao_ref_init_from_vn_reference): Likewise.
	(fully_constant_reference): Likewise.
	(vn_reference_lookup_call): Do not set vr->type to random
	values.
	* tree-ssa-pre.c (compute_avail): Do not try to PRE calls
	without a value.
	* tree-vect-generic.c (expand_vector_piecewise): Pass in
	whether we expanded parallel.
	(expand_vector_parallel): Adjust.
	(expand_vector_addition): Likewise.
	(expand_vector_comparison): Likewise.
	(expand_vector_operation): Likewise.
	(expand_vector_scalar_condition): Likewise.
	(expand_vector_conversion): Likewise.