Add some support for the code-point code-unit distinction.

runtime/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 480 matching lines @@
   }
   if (is_valid &&
       ((*code_point > 0x10FFFF) ||
        ((*code_point & 0xFFFFF800) == 0xD800))) {
     ErrorMsg("invalid code point");
   }
 }
 
 
 void Scanner::ScanLiteralStringChars(bool is_raw) {
-  GrowableArray<uint32_t> string_chars(64);
+  GrowableArray<int32_t> string_chars(64);
 
   ASSERT(IsScanningString());
   // We are at the first character of a string literal piece. A string literal
   // can be broken up into multiple pieces by string interpolation.
   while (true) {
     if ((c0_ == '\0') || ((c0_ == '\n') && !string_is_multiline_)) {
       ErrorMsg("unterminated string literal");
       EndStringLiteral();
       return;
     }
@@ skipping 440 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