The function dict_disable_redo_if_temporary() was supposed to
disable redo logging for temporary tables. It was invoked
unnecessarily for two read-only operations:
row_undo_search_clust_to_pcur() and
dict_stats_update_transient_for_index().

When a table is not temporary and not in the system tablespace,
the tablespace should be flagged for MLOG_FILE_NAME logging.
We do not need this overhead for temporary tables. Therefore,
either mtr_t::set_log_mode() or mtr_t::set_named_space() should
be invoked.

dict_table_t::is_temporary(): Determine if a table is temporary.

dict_table_is_temporary(): Redefined as a macro wrapper for
dict_table_t::is_temporary().

dict_disable_redo_if_temporary(): Remove.