fix clang build

FAILED: sql/CMakeFiles/sql.dir/sql_test.cc.o
/home/kevgs/bin/clang++ -DHAVE_CONFIG_H -DHAVE_EVENT_SCHEDULER -DHAVE_POOL_OF_THREADS -DMYSQL_SERVER -D_FILE_OFFSET_BITS=64 -Iinclude -I../include -I../sql -Ipcre -I../pcre -I../zlib -Izlib -I../extra/yassl/include -I../extra/yassl/taocrypt/include -Isql -I../wsrep -O2 -fdiagnostics-color=always -fno-omit-frame-pointer -gsplit-dwarf -march=native -mtune=native -fPIC -fno-rtti -g -DENABLED_DEBUG_SYNC -ggdb3 -DSAFE_MUTEX -Wall -Wdeclaration-after-statement -Wextra -Wformat-security -Wno-init-self -Wno-null-conversion -Wno-unused-parameter -Wno-unused-private-field -Woverloaded-virtual -Wvla -Wwrite-strings -Werror   -DHAVE_YASSL -DYASSL_PREFIX -DHAVE_OPENSSL -DMULTI_THREADED -MD -MT sql/CMakeFiles/sql.dir/sql_test.cc.o -MF sql/CMakeFiles/sql.dir/sql_test.cc.o.d -o sql/CMakeFiles/sql.dir/sql_test.cc.o -c ../sql/sql_test.cc
../sql/sql_test.cc:390:20: error: '::' and '*' tokens forming pointer to member type are separated by whitespace [-Werror,-Wcompound-token-split-by-space]
Item* (List<Item>:: *dbug_list_item_elem_ptr)(int)= &List<Item>::elem;
                 ~~^~
../sql/sql_test.cc:391:32: error: '::' and '*' tokens forming pointer to member type are separated by whitespace [-Werror,-Wcompound-token-split-by-space]
Item_equal* (List<Item_equal>:: *dbug_list_item_equal_elem_ptr)(int)=
                             ~~^~
../sql/sql_test.cc:393:32: error: '::' and '*' tokens forming pointer to member type are separated by whitespace [-Werror,-Wcompound-token-split-by-space]
TABLE_LIST* (List<TABLE_LIST>:: *dbug_list_table_list_elem_ptr)(int) =
                             ~~^~
3 errors generated.

sql/sql_test.cc

@@ -387,10 +387,10 @@ void print_sjm(SJ_MATERIALIZATION_INFO *sjm)
 /*
   Debugging help: force List<...>::elem function not be removed as unused.
 */
-Item* (List<Item>:: *dbug_list_item_elem_ptr)(int)= &List<Item>::elem;
-Item_equal* (List<Item_equal>:: *dbug_list_item_equal_elem_ptr)(int)=
+Item* (List<Item>::*dbug_list_item_elem_ptr)(int)= &List<Item>::elem;
+Item_equal* (List<Item_equal>::*dbug_list_item_equal_elem_ptr)(int)=
   &List<Item_equal>::elem;
-TABLE_LIST* (List<TABLE_LIST>:: *dbug_list_table_list_elem_ptr)(int) =
+TABLE_LIST* (List<TABLE_LIST>::*dbug_list_table_list_elem_ptr)(int) =
   &List<TABLE_LIST>::elem;
 
 #endif