[interpreter, debugger] replace bytecode on-stack for debugging.

test/mjsunit/ignition/debug-break-on-stack.js

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-debug-as debug
 
 var Debug = debug.Debug;
 
 var break_count = 0;
 var exception = null;
 
 function listener(event, exec_state, event_data, data) {
   if (event != Debug.DebugEvent.Break) return;
   try {
     break_count++;
     var line = exec_state.frame(0).sourceLineText();
+    print(line);
     assertTrue(line.indexOf(`B${break_count}`) > 0);
   } catch (e) {
     exception = e;
   }
 }
 
-Debug.setListener(listener);
 
 function g() {
-  throw 1;
+  setbreaks();
+  throw 1;  // B1
 }
 
 function f() {
   try {
-    g();                         // B1
+    g();
   } catch (e) {}
-  assertEquals(2, break_count);  // B2
-  return 1;                      // B3
+  return 2;  // B2
 }
 
-Debug.setBreakPoint(f, 2, 0);
-Debug.setBreakPoint(f, 4, 1);
-Debug.setBreakPoint(f, 5, 1);
+function setbreaks() {
+  Debug.setListener(listener);
+  Debug.setBreakPoint(g, 2, 0);
+  Debug.setBreakPoint(f, 4, 0);
+}
 
 f();
 
-assertEquals(3, break_count);
+assertEquals(2, break_count);
 assertNull(exception);
 
 Debug.setListener(null);