Bring back LX zones.

*** 630,639 ****
--- 630,641 ----
  
  /*ARGSUSED*/
  static greg_t
  fix_segreg(greg_t sr, int iscs, model_t datamodel)
  {
+         kthread_t *t = curthread;
+         
          switch (sr &= 0xffff) {
  
          case 0:
                  if (iscs == IS_CS)
                          return (0 | SEL_UPL);
*** 666,675 ****
--- 668,690 ----
          default:
                  break;
          }
  
          /*
+          * Allow this process's brand to do any necessary segment register
+          * manipulation.
+          */
+         if (PROC_IS_BRANDED(t->t_procp) && BRMOP(t->t_procp)->b_fixsegreg) {
+                 greg_t bsr = BRMOP(t->t_procp)->b_fixsegreg(sr, datamodel);
+ 
+                 if (bsr == 0 && iscs == IS_CS)
+                         return (0 | SEL_UPL);
+                 else
+                         return (bsr);
+         }
+ 
+         /*
           * Force it into the LDT in ring 3 for 32-bit processes, which by
           * default do not have an LDT, so that any attempt to use an invalid
           * selector will reference the (non-existant) LDT, and cause a #gp
           * fault for the process.
           *