Make stray 'return' an early error

src/parser.h

 // Copyright 2012 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 520 matching lines @@
   Expression* NewThrowReferenceError(const char* type, int pos);
 
   // Generate AST node that throws a SyntaxError with the given
   // type. The first argument may be null (in the handle sense) in
   // which case no arguments are passed to the constructor.
   Expression* NewThrowSyntaxError(
       const char* type, Handle<Object> arg, int pos);
 
   // Generate AST node that throws a TypeError with the given
   // type. Both arguments must be non-null (in the handle sense).
-  Expression* NewThrowTypeError(
-      const char* type, Handle<Object> arg1, Handle<Object> arg2, int pos);
+  Expression* NewThrowTypeError(const char* type, Handle<Object> arg, int pos);
 
   // Generic AST generator for throwing errors from compiled code.
   Expression* NewThrowError(
       Handle<String> constructor, const char* type,
       Vector<Handle<Object> > arguments, int pos);
 
   // Reporting errors.
   void ReportMessageAt(Scanner::Location source_location,
                        const char* message,
                        Vector<const char*> args,
@@ skipping 286 matching lines @@
  private:
   static const int kLiteralTypeSlot = 0;
   static const int kElementsSlot = 1;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CompileTimeValue);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PARSER_H_