Problem:
-------
During truncate, we intentionally crash (DBUG_SUICIDE()) after updating
SYS_INDEXES. In recovery, we skip all redo on the tablespace that was
truncated. All the LSNs > MLOG_TRUNCATE LSN are also skipped if the
tablespace is marked for truncate. Because of this, tablespace pages
are inconsistent state (depends on flush order).

Since we crashed when inserting into SYS_INDEXES, this transaction has to be
rolledback. After finishing recovery, we try to rollback the DD
transaction. When undoing the changes to SYS_INDEXES, we drop the index
of a tablespace first and undo the modification on SYS_INDEXES table.

The drop of index on the truncated tablespace causes assert because the
tablespace is in inconsistent state (the truncate fixup is yet to be done).

Fix:
----
During rollback, do not try to drop the index of tablespace if it is
marked for truncate. The tablespace will be fixed by the truncate fixup
action.

Also fixed the wl#6501 testcases to use .inc files

Reviewed-by: Krunal Bauskar <krunal.bauskar@oracle.com>
RB: 9961