Fix incorrect coercion of other failures to Failure::Exception in ReThrow.

src/runtime.cc

 // Copyright 2011 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 585 matching lines @@
       (prototype->IsJSObject() || prototype->IsJSProxy()) ? prototype
           : isolate->heap()->null_value();
   return isolate->heap()->AllocateJSProxy(handler, used_prototype);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateCatchExtensionObject) {
   ASSERT(args.length() == 2);
   CONVERT_CHECKED(String, key, args[0]);
   Object* value = args[1];
+  ASSERT(!value->IsFailure());
   // Create a catch context extension object.
   JSFunction* constructor =
       isolate->context()->global_context()->
           context_extension_function();
   Object* object;
   { MaybeObject* maybe_object = isolate->heap()->AllocateJSObject(constructor);
     if (!maybe_object->ToObject(&object)) return maybe_object;
   }
   // Assign the exception value to the catch variable and make sure
   // that the catch variable is DontDelete.
@@ skipping 11599 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal