If we seem to be out of VM, don't allow the pagedaemon to kill processes in the first pass.  Among other things, this will give us a chance to launder vnode-backed pages before concluding that we need more swap.  This is particularly useful for systems that have no swap.
If we seem to be out of VM, don't allow the pagedaemon to kill
processes in the first pass.  Among other things, this will give
us a chance to launder vnode-backed pages before concluding that
we need more swap.  This is particularly useful for systems that
have no swap.

While here, update a comment and remove some long-unused code.

Reported by:	Lucky Green <shamrock@cypherpunks.to>
Suggested by:	dillon
Approved by:	re (rwatson)

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase