Update Trace Linking Rules comment

Author: arnaud-lb

ext/opcache/jit/zend_jit_vm_helpers.c

@@ -615,9 +615,9 @@ static int zend_jit_trace_subtrace(zend_jit_trace_rec *trace_buffer, int start,
  *
  *                                          flags
  *          +----------+----------+----------++----------+----------+----------+
- *          |                                ||              JIT               |
+ *          |                                ||  When meeting a JIT'ed opline  |
  *          +----------+----------+----------++----------+----------+----------+
- *   start  |   LOOP   |  ENTER   |  RETURN  ||   LOOP   |  ENTER   |  RETURN  |
+ *  start v |   LOOP   |  ENTER   |  RETURN  ||   LOOP   |  ENTER   |  RETURN  |
  * +========+==========+==========+==========++==========+==========+==========+
  * | LOOP   |   loop   |          | loop-ret || COMPILED |   LINK   |   LINK   |
  * +--------+----------+----------+----------++----------+----------+----------+
@@ -637,7 +637,7 @@ static int zend_jit_trace_subtrace(zend_jit_trace_rec *trace_buffer, int start,
  * return:     RETURN if level == 0
  * rec_ret:    RECURSIVE_RET if "cycle" and ret_level > N, otherwise continue
  * side_ret:   RETURN if level == 0 && ret_level == ret_depth, otherwise continue
- *
+ * LINK:       stop recording. End of new trace jumps to the other one.
  */
 
 zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data  *ex,