MFC r281720
Eliminate an unused variable.

MFC r298891:
Avoid duplicated calls to pmap_page_get_memattr().
Avoid logging inconsistency for the /dev/mem device.

MFC r291446:
Minor cleanup.

Systematically use ANSI C functions definitions.
Correct type of the flags argument to the dev_pager_putpages() function.

vm_pager_free_nonreq() does not exist in stable/10, this part is not
merged.

MFC 261811,282660,282706:
Place VM objects on the object list when created and never remove them.

261811:
Fix function name in KASSERT().

282660:
Place VM objects on the object list when created and never remove them.
This is ok since objects come from a NOFREE zone and allows objects to
be locked while traversing the object list without triggering a LOR.

Ensure that objects on the list are marked DEAD while free or stillborn,
and that they have a refcount of zero. This required updating most of
the pagers to explicitly mark an object as dead when deallocating it.
(Only the vnode pager did this previously.)

282706:
Satisfy vm_object uma zone destructor requirements after r282660 when
vnode object creation raced.

MFC r263095:
Initialize paddr to handle the case of zero size.

MFC 261811,282660,282706:
Place VM objects on the object list when created and never remove them.

261811:
Fix function name in KASSERT().

282660:
Place VM objects on the object list when created and never remove them.
This is ok since objects come from a NOFREE zone and allows objects to
be locked while traversing the object list without triggering a LOR.

Ensure that objects on the list are marked DEAD while free or stillborn,
and that they have a refcount of zero. This required updating most of
the pagers to explicitly mark an object as dead when deallocating it.
(Only the vnode pager did this previously.)

282706:
Satisfy vm_object uma zone destructor requirements after r282660 when
vnode object creation raced.

MFC r263095:
Initialize paddr to handle the case of zero size.