tree-optimization/109721 - emulated vectors

When fixing PR109672 I noticed we let SImode AND through when
target_support_p even though it isn't word_mode and I didn't want to
change that but had to catch the case where SImode PLUS is supported
but emulated vectors rely on it being word_mode.  The following
makes sure to preserve the word_mode check when !target_support_p
to avoid excessive lowering later even for bit operations.

	PR tree-optimization/109721
	* tree-vect-stmts.cc (vectorizable_operation): Make sure
	to test word_mode for all !target_support_p operations.