completely remove old InnoDB system tables:

    1. WL#9535: InnoDB_New_DD: Remove InnoDB System Table and modify the
    view of their I_S counterparts

    This worklog obsoletes all InnoDB System tables, which are no longer
    used and could only be accessed by upgrade. All metadata is now
    persisted and read from DD system tables in "mysql tablespace"
    instead of "old" InnoDB System Tables.

    All corresponding information_schema.innodb_sys_* tables are replaced
    by new internal system views.
    These new views have the name similar to the names of old system tables,
    just removing the 'SYS_' from the middle of the names.

    2. WL#9536: InnoDB_New_DD: Support crash-safe DDL

    This worklog starts to support crash-safe DDL for InnoDB. DDLs like
    CREATE TABLE, DROP TABLE, RENAME TABLE, TRUNCATE TABLE, ALTER TABLE,
    CREATE TABLESPACE and DROP TABLESPACE are covered by this worklog.
    DDLs operations including DD system table updates and corresponding
    file changes(create, delete, rename etc.) are atomic.

    Physical data files would be synchronized with the transaction for DDL,
    thus there should be no physical data files for temporary tables or FTS
    auxiliary tables, etc. left after recovery.