Merge from FreeBSD, RELENG_4 branch, revision 1.250.2.26.

Merge from FreeBSD, RELENG_4 branch, revision 1.250.2.26.

	--- original commit message ---
	  Log:
	  There is a comma missing in the table initializing the
	  pmap_prefault_pageorder array.  This has two effects:

	  1. The resulting bogus contents of the array thwarts part of
	  the optimization effect pmap_prefault() is supposed to have.

	  2. The resulting array is only 7 elements long (auto-sized), while
	  pmap_prefault() expects it to be the intended 8 elements.  So
	  this function in fact accesses memory beyond the end of the array.
	  Fortunately though, if the data at this location is out of bounds
	  it will be ignored.

	  This bug dates back more than 6 years.  It has been introduced
	  in revision 1.178.

	  Submitted by:   Uwe Doering <gemini@geminix.org>
	  PR:     		  67460
	--- original commit message ---