Upgrade to new CHR (with Jan's changes).

Found out I need to add an extra field to allocate so that the
exception handling code knows where the clause is.
Protect creep_allowed from NULL pointers.

C/tracer.c

@@ -164,6 +164,10 @@ low_level_trace(yap_low_level_port port, PredEntry *pred, CELL *args)
   LOCK(Yap_heap_regs->low_level_trace_lock);
   sc = Yap_heap_regs;
   vsc_count++;
+  if (vsc_count < 2473000LL)
+    return;
+  if (vsc_count == 2473801LL)
+    jmp_deb(1);
 #ifdef THREADS
   Yap_heap_regs->thread_handle[worker_id].thread_inst_count++;
 #endif