Fix 16099: Invocation's positionalArguments contains an immutable array.

runtime/lib/array.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 "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
@@ skipping 92 matching lines @@
     }
   } else {
     for (intptr_t i = 0; i < icount; i++) {
       src_obj = source.At(isrc_start + i);
       dest.SetAt(idst_start + i, src_obj);
     }
   }
   return Object::null();
 }
 
+
+// Private factory, expects correct arguments.
+DEFINE_NATIVE_ENTRY(ImmutableList_from, 4) {
+  // Ignore first argument of a thsi factory (type argument).
+  const Array& from_array = Array::CheckedHandle(arguments->NativeArgAt(1));
+  const Smi& smi_offset = Smi::CheckedHandle(arguments->NativeArgAt(2));
+  const Smi& smi_length = Smi::CheckedHandle(arguments->NativeArgAt(3));
+  const intptr_t length = smi_length.Value();
+  const intptr_t offset = smi_offset.Value();
+  const Array& result = Array::Handle(Array::New(length));
+  Object& temp = Object::Handle();
+  for (intptr_t i = 0; i < length; i++) {
+    temp = from_array.At(i + offset);
+    result.SetAt(i, temp);
+  }
+  result.MakeImmutable();
+  return result.raw();
+}
+
 }  // namespace dart