Revert "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, 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");
-  });
-
-function listener(event, exec_state, event_data, data) {
-  try {
-    assertTrue(event != Debug.DebugEvent.Exception);
-  } 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);