Do not copy immutable arrays in String.createFromCharCodes. Tighten the types a little in string_pa…

runtime/lib/string.cc

 // Copyright (c) 2011, 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/bootstrap_natives.h"
 
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/symbols.h"
 #include "vm/unicode.h"
 
 namespace dart {
 
 DEFINE_NATIVE_ENTRY(StringBase_createFromCodePoints, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, list, arguments->NativeArgAt(0));
   if (!list.IsGrowableObjectArray() && !list.IsArray()) {
     const Array& args = Array::Handle(Array::New(1));
     args.SetAt(0, list);
     Exceptions::ThrowByType(Exceptions::kArgument, args);
   }
-  // TODO(srdjan): Check that parameterized type is an int.
 
   Array& a = Array::Handle();
   intptr_t array_len;
   if (list.IsGrowableObjectArray()) {
     const GrowableObjectArray& growableArray = GrowableObjectArray::Cast(list);
     a ^= growableArray.data();
     array_len = growableArray.Length();
   } else {
     a ^= Array::Cast(list).raw();
     array_len = a.Length();
@@ skipping 196 matching lines @@
       ? String::Handle(OneByteString::New(length_value, Heap::kNew))
       : String::Handle(TwoByteString::New(length_value, Heap::kNew));
   NoGCScope no_gc;
 
   uint16_t* data_position = reinterpret_cast<uint16_t*>(codeUnits.DataAddr(0));
   String::Copy(result, 0, data_position, length_value);
   return result.raw();
 }
 
 }  // namespace dart