MFC r233168:

MFC r233168:
If we ever allow for managed fictitious pages, the pages shall be
excluded from superpage promotions.  At least one of the reason is
that pv_table is sized for non-fictitious pages only.

Consistently check for the page to be non-fictitious before accesing
superpage pv list.

MFC note: erronous chunks from r233168 which were fixed in r233185
are not included into the merge.

git-svn-id: svn://svn.freebsd.org/base/stable/9@233775 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f