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

runtime/vm/scopes.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/scopes.h"
 
 #include "vm/ast.h"
 #include "vm/bit_vector.h"
 #include "vm/object.h"
 #include "vm/parser.h"
@@ skipping 196 matching lines @@
   for (int i = 0; i < vars.length(); i++) {
     var_desc.SetVar(i, *(vars[i].name), &vars[i].info);
   }
   return var_desc.raw();
 }
 
 
 // The parser creates internal variables that start with ":"
 static bool IsInternalIdentifier(const String& str) {
   ASSERT(str.Length() > 0);
-  return str.CharAt(0) == ':';
+  return str.CodeUnitAt(0) == ':';
 }
 
 
 // Add variables that are declared in this scope to vars, then collect
 // variables of children, followed by siblings.
 void LocalScope::CollectLocalVariables(GrowableArray<VarDesc>* vars,
                                        int16_t* scope_id) {
   (*scope_id)++;
   if (HasContextLevel() &&
       ((parent() == NULL) ||
@@ skipping 323 matching lines @@
   } else {
     // Shift negative indexes so that the lowest one is 0 (they are still
     // non-positive).
     return fixed_parameter_count -
         (index() - ParsedFunction::kFirstLocalSlotIndex);
   }
 }
 
 
 }  // namespace dart