[ntuple] add RNTupleUtil.hxx compatibility header

Author: jblomer

tree/ntuple/CMakeLists.txt

@@ -38,6 +38,7 @@ HEADERS
   ROOT/RNTupleReader.hxx
   ROOT/RNTupleSerialize.hxx
   ROOT/RNTupleTypes.hxx
+  ROOT/RNTupleUtil.hxx
   ROOT/RNTupleUtils.hxx
   ROOT/RNTupleView.hxx
   ROOT/RNTupleWriteOptions.hxx

tree/ntuple/inc/ROOT/RNTupleUtil.hxx

@@ -0,0 +1,24 @@
+/// \file ROOT/RNTupleUtil.hxx
+/// \ingroup NTuple
+/// \author Jakob Blomer <[email protected]>
+/// \date 2025-07-31
+
+/*************************************************************************
+ * Copyright (C) 1995-2025, Rene Brun and Fons Rademakers.               *
+ * All rights reserved.                                                  *
+ *                                                                       *
+ * For the licensing terms see $ROOTSYS/LICENSE.                         *
+ * For the list of contributors see $ROOTSYS/README/CREDITS.             *
+ *************************************************************************/
+
+#ifndef ROOT_RNTupleUtil
+#define ROOT_RNTupleUtil
+
+#if !defined(R__NO_DEPRECATION) && !defined(__CLING__)
+#warning "<ROOT/RNTupleUtil.hxx> is deprecated and will be removed in ROOT v6.40. Use <ROOT/RNTupleTypes.hxx>."
+#endif
+
+#include <ROOT/RNTupleTypes.hxx>
+#include <ROOT/RNTupleUtils.hxx>
+
+#endif