Fix the ScopeIterator reimplemantation.

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index 8b34f022fc53d4f3d4858dfbbeb94835f291c66c..e4d278d2e1b3c743a517d01a28fdc94c7b3f695d 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -488,14 +488,7 @@ Handle<SharedFunctionInfo> Compiler::Compile(Handle<String> source,
     }
     if (pre_data == NULL
         && source_length >= FLAG_min_preparse_length) {
-      if (source->IsExternalTwoByteString()) {
-        ExternalTwoByteStringUC16CharacterStream stream(
-            Handle<ExternalTwoByteString>::cast(source), 0, source->length());
-        pre_data = ParserApi::PartialPreParse(&stream, extension, flags);
-      } else {
-        GenericStringUC16CharacterStream stream(source, 0, source->length());
-        pre_data = ParserApi::PartialPreParse(&stream, extension, flags);
-      }
+      pre_data = ParserApi::PartialPreParse(source, extension, flags);
     }
 
     // Create a script object describing the script to be compiled.