created in fast index creation.

dict_load_indexes(): Always complain if the first index is not clustered.

lock_table_enqueue_waiting(): Always complain about lock waits in
a dictionary operation.

row_merge_rename_tables(): Add an assertion that dict_sys->mutex is
being held.

row_undo_mod_del_unmark_sec_and_undo_update(): Make the test about
temporary indexes more readable.

row_create_table_for_mysql(): Do not retry creating a temporary table
in fast index creation.  Orphaned temporary tables will have to be dropped
in crash recovery.