For data and instruction prefetch aborts, call the same handler in the C
code, passing a 0/1 flag that indicates which type of abort it was.  This
sets the stage for unifying the handling of page faults in a single routine.

Submitted by: Svatopluk Kraus <onwahe@gmail.com>,
	      Michal Meloun <meloun@miracle.cz


git-svn-id: svn+ssh://svn.freebsd.org/base/head@276206 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f