remove whole-process swapping
Long before Unix supported paging, it used process swapping to reclaim
memory.  The code is there and in theory it runs when we get *extremely* low
on memory.  In practice, it never runs since the definition of low-on-memory
is antiquated. (XXX: define what antiquated means)
You can check the number of swapout/swapin events with kstats:
$ kstat -p ::vm:swapin ::vm:swapout

@@ -357,12 +357,10 @@
         struct regs *rp = lwptoregs(lwp);
         int     repost;
 
         t->t_pre_sys = repost = 0;      /* clear pre-syscall processing flag */
 
-        ASSERT(t->t_schedflag & TS_DONT_SWAP);
-
         syscall_mstate(LMS_USER, LMS_SYSTEM);
 
         /*
          * The syscall arguments in the out registers should be pointed to
          * by lwp_ap.  If the args need to be copied so that the outs can