Fix for issue 7089 (Symbols::New was not quite working correctly

vm/scanner.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/scanner.h"
 
 #include "platform/assert.h"
 #include "vm/flags.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
@@ skipping 565 matching lines @@
           }
           escape_char = c0_;
           break;
       }
       string_chars.Add(escape_char);
     } else if (c0_ == '$' && !is_raw) {
       // Scanned a string piece.
       ASSERT(string_chars.data() != NULL);
       // Strings are canonicalized: Allocate a symbol.
       current_token_.literal = &String::ZoneHandle(
-          Symbols::New(string_chars.data(), string_chars.length()));
+          Symbols::FromUTF32(string_chars.data(), string_chars.length()));
       // Preserve error tokens.
       if (current_token_.kind != Token::kERROR) {
         current_token_.kind = Token::kSTRING;
       }
       return;
     } else if (c0_ == string_delimiter_) {
       // Check if we are at the end of the string literal.
       if (!string_is_multiline_ ||
           ((LookaheadChar(1) == string_delimiter_) &&
            (LookaheadChar(2) == string_delimiter_))) {
         if (string_is_multiline_) {
           ReadChar();  // Skip two string delimiters.
           ReadChar();
         }
         // Preserve error tokens.
         if (current_token_.kind == Token::kERROR) {
           ReadChar();
         } else {
           Recognize(Token::kSTRING);
           ASSERT(string_chars.data() != NULL);
           // Strings are canonicalized: Allocate a symbol.
           current_token_.literal = &String::ZoneHandle(
-              Symbols::New(string_chars.data(), string_chars.length()));
+              Symbols::FromUTF32(string_chars.data(), string_chars.length()));
         }
         EndStringLiteral();
         return;
       } else {
         string_chars.Add(string_delimiter_);
       }
     } else {
       string_chars.Add(c0_);
     }
     ReadChar();
@@ skipping 366 matching lines @@
               "%c%#"Px"", kPrivateKeySeparator, key_value);
   const String& result = String::Handle(String::New(private_key, Heap::kOld));
   return result.raw();
 }
 
 
 void Scanner::InitOnce() {
 }
 
 }  // namespace dart