Adding compound assignments to the top-level compiler.

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 1223 matching lines @@
 
   virtual void Accept(AstVisitor* v);
   virtual Assignment* AsAssignment() { return this; }
 
   Token::Value binary_op() const;
 
   Token::Value op() const { return op_; }
   Expression* target() const { return target_; }
   Expression* value() const { return value_; }
   int position() { return pos_; }
+  // This check relies on the definition order of token in token.h.
+  bool is_compound() const { return op() > Token::ASSIGN; }
 
   // An initialization block is a series of statments of the form
   // x.y.z.a = ...; x.y.z.b = ...; etc. The parser marks the beginning and
   // ending of these blocks to allow for optimizations of initialization
   // blocks.
   bool starts_initialization_block() { return block_start_; }
   bool ends_initialization_block() { return block_end_; }
   void mark_block_start() { block_start_ = true; }
   void mark_block_end() { block_end_ = true; }
 
@@ skipping 527 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_