Fix compile errors.

Author: sanja-byelkin

sql/sql_select.h

@@ -1265,7 +1265,7 @@ class JOIN :public Sql_alloc
 
 #ifndef DBUG_OFF
   void dbug_verify_sj_inner_tables(uint n_positions) const;
-  uint dbug_join_tab_array_size;
+  int dbug_join_tab_array_size;
 #endif
 
   /* We also maintain a stack of join optimization states in * join->positions[] */