[lno] [patch] bring over vectorizer changes from mainline

[Dorit Naishlos]

> The pointer alignment pass on lno needs to be rewritten to use tree-ssa-
> propagate, which exists on mainline but not lno.
> I can rewrite it just for mainline if you planned on submitting it for
> 4.0, i can't remember whether that was the case or not.

Unfortunately I didn't explicitly mention it on the vectorizer patch list
for 4.0, although it is used by the vectorizer in lno. I guess it's too
late now?

dorit