Fix compilation with clang

src/scanner-character-streams.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 195 matching lines @@
     } else {
       buffer_[i++] = static_cast<uc16>(c);
     }
   }
   raw_character_position_ = char_position + i;
   return i;
 }
 
 
 static const byte kUtf8MultiByteMask = 0xC0;
-static const byte kUtf8MultiByteCharStart = 0xC0;
 static const byte kUtf8MultiByteCharFollower = 0x80;
 
 
 #ifdef DEBUG
+static const byte kUtf8MultiByteCharStart = 0xC0;
 static bool IsUtf8MultiCharacterStart(byte first_byte) {
   return (first_byte & kUtf8MultiByteMask) == kUtf8MultiByteCharStart;
 }
 #endif
 
 
 static bool IsUtf8MultiCharacterFollower(byte later_byte) {
   return (later_byte & kUtf8MultiByteMask) == kUtf8MultiByteCharFollower;
 }
 
@@ skipping 85 matching lines @@
         int end_position)
     : Utf16CharacterStream(),
       source_(data),
       raw_data_(data->GetTwoByteData(start_position)) {
   buffer_cursor_ = raw_data_,
   buffer_end_ = raw_data_ + (end_position - start_position);
   pos_ = start_position;
 }
 
 } }  // namespace v8::internal