Fixes minor bugs in XLA-specific code. (#361)

src/ngraph/builder/xla_tuple.hpp

@@ -87,7 +87,7 @@ namespace ngraph
         };
 
         /// Convenience function for making a runtime tuple.
-        std::shared_ptr<XLATuple> make_tuple(const XLAValues& elements)
+        inline std::shared_ptr<XLATuple> make_tuple(const XLAValues& elements)
         {
             return std::make_shared<XLATuple>(elements);
         }

src/ngraph/ngraph.hpp

@@ -41,6 +41,12 @@
 /// @brief Convenience functions that create addional graph nodes to implement commonly-used
 ///        recipes, for example auto-broadcast.
 
+/// @namespace ngraph::xla
+/// @brief Code to facilitate nGraph's support for XLA/HLO.
+
+/// @namespace ngraph::xla::op
+/// @brief Operators specific to nGraph's support for XLA/HLO.
+
 #include "ngraph/builder/autobroadcast.hpp"
 #include "ngraph/builder/numpy_transpose.hpp"
 #include "ngraph/builder/reduce_ops.hpp"