Handle mixing REALPART/IMAGPART with other components in SLP groups

The following makes sure we handle a SLP load/store group from
a structure with complex and scalar members.  This for example
happens in gcc.target/i386/pr106010-9a.c.

	* tree-vect-slp.cc (vect_build_slp_tree_1): Handle mixing
	all of handled components besides ARRAY_RANGE_REF, drop
	handling of INDIRECT_REF.