slots again: make sure they're bound after resetting the stack and when calling InitForeign

C/c_interface.c

@@ -3394,6 +3394,9 @@ YAP_Reset(void)
   /* the first real choice-point will also have AP=FAIL */ 
   /* always have an empty slots for people to use */
   P = CP = YESCODE;
+  // ensure that we have slots where we need them
+  LOCAL_CurSlot = 0;
+  Yap_StartSlots( PASS_REGS1 );
   RECOVER_MACHINE_REGS();
   return res;
 }