xAODTrigger: Fix compilation failure with clang.

operator<< should be declared within the namespace of its argument
so that argument-dependent lookup will work properly.

Event/xAOD/xAODTrigger/Root/TrigComposite_v1.cxx

@@ -278,7 +278,6 @@ namespace xAOD {
    //
    /////////////////////////////////////////////////////////////////////////////
 
-} // namespace xAOD
 
 std::ostream& operator<<(std::ostream& os, const xAOD::TrigComposite_v1& tc) {
   os << "TrigComposite_v1 '" << tc.name() << "' link: name, key, index, CLID" << std::endl;
@@ -290,3 +289,5 @@ std::ostream& operator<<(std::ostream& os, const xAOD::TrigComposite_v1& tc) {
   }
   return os;
 }
+
+} // namespace xAOD

Event/xAOD/xAODTrigger/xAODTrigger/versions/TrigComposite_v1.h

 // Dear emacs, this is -*- c++ -*-
 
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 // $Id: TrigComposite_v1.h 784388 2016-11-15 17:08:58Z tamartin $
@@ -183,15 +183,15 @@ namespace xAOD {
 
    }; // class TrigComposite_v1
 
-} // namespace xAOD
-
-// Include the template implementation:
-#include "TrigComposite_v1.icc"
-
 /**
  * @brief print helper for TrigComposite
  */
 std::ostream& operator<<(std::ostream& os, const xAOD::TrigComposite_v1& tc);
 
 
+} // namespace xAOD
+
+// Include the template implementation:
+#include "TrigComposite_v1.icc"
+
 #endif // XAODTRIGGER_VERSIONS_TRIGCOMPOSITE_V1_H