Allow microtasks to throw exceptions and handle them gracefully

src/isolate.h

 // Copyright 2012 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.
 
 #ifndef V8_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include "../include/v8-debug.h"
 #include "allocation.h"
 #include "assert-scope.h"
@@ skipping 738 matching lines @@
   bool ShouldReportException(bool* can_be_caught_externally,
                              bool catchable_by_javascript);
 
   // Attempts to compute the current source location, storing the
   // result in the target out parameter.
   void ComputeLocation(MessageLocation* target);
 
   // Out of resource exception helpers.
   Object* StackOverflow();
   Object* TerminateExecution();
+  bool IsExecutionTerminating();
   void CancelTerminateExecution();
 
   void InvokeApiInterruptCallback();
 
   // Administration
   void Iterate(ObjectVisitor* v);
   void Iterate(ObjectVisitor* v, ThreadLocalTop* t);
   char* Iterate(ObjectVisitor* v, char* t);
   void IterateThread(ThreadVisitor* v, char* t);
 
@@ skipping 714 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_