Revert the exception propagation fix. It leads to crashes because...

src/top.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 140 matching lines @@
     return thread_local_.scheduled_exception_;
   }
   static bool has_scheduled_exception() {
     return !thread_local_.scheduled_exception_->IsTheHole();
   }
   static void clear_scheduled_exception() {
     thread_local_.scheduled_exception_ = Heap::the_hole_value();
   }
 
   static void setup_external_caught() {
-    if (!thread_local_.external_caught_exception_) {
-      thread_local_.external_caught_exception_ =
-          has_pending_exception() &&
-          (thread_local_.catcher_ != NULL) &&
-          (thread_local_.try_catch_handler_ == thread_local_.catcher_);
-    }
+    thread_local_.external_caught_exception_ =
+        (!thread_local_.pending_exception_->IsTheHole()) &&
+        (thread_local_.catcher_ != NULL) &&
+        (Top::thread_local_.try_catch_handler_ == Top::thread_local_.catcher_);
   }
 
   // Tells whether the current context has experienced an out of memory
   // exception.
   static bool is_out_of_memory();
 
   // JS execution stack (see frames.h).
   static Address c_entry_fp(ThreadLocalTop* thread) {
     return thread->c_entry_fp_;
   }
@@ skipping 194 matching lines @@
 
 class ExecutionAccess BASE_EMBEDDED {
  public:
   ExecutionAccess();
   ~ExecutionAccess();
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_TOP_H_