Make native syntax an early error in the preparser.

src/preparser.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 1335 matching lines @@
     return Expression::StrictFunction();
   }
 
   return Expression::Default();
 }
 
 
 PreParser::Expression PreParser::ParseV8Intrinsic(bool* ok) {
   // CallRuntime ::
   //   '%' Identifier Arguments
-
   Expect(i::Token::MOD, CHECK_OK);
+  if (!allow_natives_syntax_) {
+    *ok = false;
+    return Expression::Default();
+  }
   ParseIdentifier(CHECK_OK);
   ParseArguments(ok);
 
   return Expression::Default();
 }
 
 #undef CHECK_OK
 
 
 void PreParser::ExpectSemicolon(bool* ok) {
@@ skipping 312 matching lines @@
       backing_store_.Add(static_cast<byte>((ascii_length >> 14) | 0x80u));
     }
     backing_store_.Add(static_cast<byte>((ascii_length >> 7) | 0x80u));
   }
   backing_store_.Add(static_cast<byte>(ascii_length & 0x7f));
 
   backing_store_.AddBlock(bytes);
   return backing_store_.EndSequence().start();
 }
 } }  // v8::preparser