WL#5030: Splitting mysql_priv.h

Adding my_global.h first in all files using
NO_EMBEDDED_ACCESS_CHECKS.

Correcting a merge problem resulting from a changed definition
of check_some_access compared to the original patches.

sql/sql_cache.cc

@@ -327,6 +327,7 @@ TODO list:
       (This could be done with almost no speed penalty)
 */
 
+#include "my_global.h"                          /* NO_EMBEDDED_ACCESS_CHECKS */
 #include "sql_priv.h"
 #include "sql_cache.h"
 #include "sql_parse.h"                          // check_table_access