finish off the factoring optimization along the lines of the

current design.  This generates a matcher that successfully
runs, but it turns out that the factoring we're doing violates
the ordering of patterns, so we end up matching (e.g.) movups
where we want movaps.  This won't due, but I'll address this in
a follow on patch.  It's nice to not be on by default yet! :)

llvm-svn: 97215