Eliminate some virtual function from AST classes.

src/ast.cc

 // Copyright 2011 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 30 matching lines @@
 
 #define DECL_ACCEPT(type)                                       \
   void type::Accept(AstVisitor* v) { v->Visit##type(this); }
 AST_NODE_LIST(DECL_ACCEPT)
 #undef DECL_ACCEPT
 
 
 // ----------------------------------------------------------------------------
 // Implementation of other node functionality.
 
-Assignment* ExpressionStatement::StatementAsSimpleAssignment() {
-  return (expression()->AsAssignment() != NULL &&
-          !expression()->AsAssignment()->is_compound())
-      ? expression()->AsAssignment()
-      : NULL;
+
+bool Expression::IsSmiLiteral() {
+  return AsLiteral() != NULL && AsLiteral()->handle()->IsSmi();
 }
 
 
-CountOperation* ExpressionStatement::StatementAsCountOperation() {
-  return expression()->AsCountOperation();
+bool Expression::IsStringLiteral() {
+  return AsLiteral() != NULL && AsLiteral()->handle()->IsString();
+}
+
+
+bool Expression::IsNullLiteral() {
+  return AsLiteral() != NULL && AsLiteral()->handle()->IsNull();
 }
 
 
 VariableProxy::VariableProxy(Isolate* isolate, Variable* var)
     : Expression(isolate),
       name_(var->name()),
       var_(NULL),  // Will be set by the call to BindTo.
       is_this_(var->is_this()),
       is_trivial_(false),
       position_(RelocInfo::kNoPosition) {
@@ skipping 1117 matching lines @@
                        int pos)
     : label_(label),
       statements_(statements),
       position_(pos),
       compare_type_(NONE),
       compare_id_(AstNode::GetNextId(isolate)),
       entry_id_(AstNode::GetNextId(isolate)) {
 }
 
 } }  // namespace v8::internal