Fix a couple cast errors

src/ast.h

 // Copyright 2010 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 1373 matching lines @@
 
 class BinaryOperation: public Expression {
  public:
   BinaryOperation(Token::Value op,
                   Expression* left,
                   Expression* right,
                   int pos)
       : op_(op), left_(left), right_(right), pos_(pos), is_smi_only_(false) {
     ASSERT(Token::IsBinaryOp(op));
     right_id_ = (op == Token::AND || op == Token::OR)
-        ? GetNextId()
+        ? static_cast<int>(GetNextId())
         : AstNode::kNoNumber;
   }
 
   // Create the binary operation corresponding to a compound assignment.
   explicit BinaryOperation(Assignment* assignment);
 
   DECLARE_NODE_TYPE(BinaryOperation)
 
   virtual bool IsInlineable() const;
 
@@ skipping 755 matching lines @@
   AST_NODE_LIST(DEF_VISIT)
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_