Fixed clang compilation

include/Base_Session.h

@@ -1,5 +1,3 @@
-template<typename S, typename DSi, typename B, typename T> class Base_Session;
-
 //// avoid loading definition of MySQL_Session and PgSQL_Session
 //#define __CLASS_MYSQL_SESSION_H
 //#define __CLASS_PGSQL_SESSION_H

include/MySQL_Session.h

@@ -445,7 +445,13 @@ class MySQL_Session: public Base_Session<MySQL_Session, MySQL_Data_Stream, MySQL
 	void set_previous_status_mode3(bool allow_execute=true);
 
 	friend void SQLite3_Server_session_handler(MySQL_Session*, void *_pa, PtrSize_t *pkt);
+
+#if defined(__clang__)
+	template<typename SESS, typename DS, typename BE, typename THD>
+	friend class Base_Session;
+#else
 	friend class Base_Session<MySQL_Session, MySQL_Data_Stream, MySQL_Backend, MySQL_Thread>;
+#endif
 };
 
 #define KILL_QUERY       1

include/PgSQL_Session.h

@@ -590,7 +590,12 @@ public:
 	void generate_status_one_hostgroup(int hid, std::string& s);
 	void set_previous_status_mode3(bool allow_execute = true);
 
+#if defined(__clang__)
+	template<typename SESS, typename DS, typename BE, typename THD>
+	friend class Base_Session;
+#else
 	friend class Base_Session<PgSQL_Session, PgSQL_Data_Stream, PgSQL_Backend, PgSQL_Thread>;
+#endif
 };