Reland "Trigger exception debug event for promises at the throw site."

test/mjsunit/es6/debug-promises-caught-late.js

 // Copyright 2014 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: --harmony-promises --expose-debug-as debug
 
-// Test debug events when we only listen to uncaught exceptions and
-// there is a catch handler for the exception thrown in a Promise.
-// Expectation:
-//  - no debug event is triggered.
+// Test debug events when we only listen to uncaught exceptions, the Promise
+// throws, and a catch handler is installed right before throwing.
+// We expect no debug event to be triggered.
 
 Debug = debug.Debug;
 
 var p = new Promise(function(resolve, reject) {
   resolve();
 });
 
 var q = p.chain(
   function() {
+    q.catch(function(e) {
+      assertEquals("caught", e.message);
+    });
     throw new Error("caught");
   });
 
-q.catch(
-  function(e) {
-    assertEquals("caught", e.message);
-  });
-
 function listener(event, exec_state, event_data, data) {
   try {
     assertTrue(event != Debug.DebugEvent.Exception);
-    assertTrue(event != Debug.DebugEvent.PendingExceptionInPromise);
   } catch (e) {
     // Signal a failure with exit code 1.  This is necessary since the
     // debugger swallows exceptions and we expect the chained function
     // and this listener to be executed after the main script is finished.
     print("Unexpected exception: " + e + "\n" + e.stack);
     quit(1);
   }
 }
 
 Debug.setBreakOnUncaughtException();
 Debug.setListener(listener);