Add a pass for the fast compiler to label expression nodes....

src/ast.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 162 matching lines @@
     // Evaluated for control flow (and side effects).
     kTest,
     // Evaluated for control flow and side effects.  Value is also
     // needed if true.
     kValueTest,
     // Evaluated for control flow and side effects.  Value is also
     // needed if false.
     kTestValue
   };
 
+  static const int kNoLabel = -1;
+
+  Expression() : num_(kNoLabel) {}
+
   virtual Expression* AsExpression()  { return this; }
 
   virtual bool IsValidJSON() { return false; }
   virtual bool IsValidLeftHandSide() { return false; }
 
   // Symbols that cannot be parsed as array indices are considered property
   // names.  We do not treat symbols that can be array indexes as property
   // names because [] for string objects is handled only by keyed ICs.
   virtual bool IsPropertyName() { return false; }
 
   // Mark the expression as being compiled as an expression
   // statement. This is used to transform postfix increments to
   // (faster) prefix increments.
   virtual void MarkAsStatement() { /* do nothing */ }
 
   // Static type information for this expression.
   StaticType* type() { return &type_; }
 
+  int num() { return num_; }
+
+  // AST node numbering ordered by evaluation order.
+  void set_num(int n) { num_ = n; }
+
  private:
   StaticType type_;
+  int num_;
 };
 
 
 /**
  * A sentinel used during pre parsing that represents some expression
  * that is a valid left hand side without having to actually build
  * the expression.
  */
 class ValidLeftHandSideSentinel: public Expression {
  public:
@@ skipping 1592 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_