[V8] Unify get function name for debugging purpose

include/v8.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.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
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   /**
    * Name inferred from variable or property assignment of this function.
    * Used to facilitate debugging and profiling of JavaScript code written
    * in an OO style, where many functions are anonymous but are assigned
    * to object properties.
    */
   Local<Value> GetInferredName() const;
 
   /**
+   * displayName if it is set, otherwise name if it is configured, otherwise
+   * function name, otherwise inferred name.
+   */
+  Local<Value> GetDebugName() const;
+
+  /**
    * User-defined name assigned to the "displayName" property of this function.
    * Used to facilitate debugging and profiling of JavaScript code.
    */
   Local<Value> GetDisplayName() const;
 
   /**
    * Returns zero based line number of function body and
    * kLineOffsetNotFound if no information available.
    */
   int GetScriptLineNumber() const;
@@ skipping 5195 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_