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

runtime/vm/dart_api_impl.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 "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 1561 matching lines @@
 
 
 DART_EXPORT Dart_Handle Dart_NewStringFromUTF32(const uint32_t* utf32_array,
                                                 intptr_t length) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   if (utf32_array == NULL && length != 0) {
     RETURN_NULL_ERROR(utf32_array);
   }
   CHECK_LENGTH(length, String::kMaxElements);
-  return Api::NewHandle(isolate, String::New(utf32_array, length));
+  return Api::NewHandle(
+      isolate,
+      String::New(reinterpret_cast<const int32_t*>(utf32_array), length));
 }
 
 
 DART_EXPORT bool Dart_IsExternalString(Dart_Handle object) {
   return RawObject::IsExternalStringClassId(Api::ClassId(object));
 }
 
 
 DART_EXPORT Dart_Handle Dart_ExternalStringGetPeer(Dart_Handle object,
                                                    void** peer) {
@@ skipping 2899 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success(isolate);
 }
 
 }  // namespace dart