POST FIX
==========
Removed the check for HT_HIDDEN_SE from lock_table_names() which is called
frequently, and added it to mysql_rename_tables() which is the only place
not covered by other checks. This fixed the regression problem.

BUG#26271244 - ASSERT FAILS WHEN SHOW CREATE TABLE CALLED ON A FILE
CREATED FOR FULLTEXT INDEX

Analysis of Initial Problem
========
a) FTS indexes are represented as hidden tables which do not show
up when doing SHOW TABLES. Yet their .ibd files are in the schema
directory and issuing SHOW CREATE TABLE on the corresponding table name
would trigger an assert.

b) Other issues revealed themselves while digging into the bug.
OPTIMIZE, REPAIR, TRUNCATE and LOCK TABLES all asserted, while
RENAME and DROP TABLE was allowed.

FIX
======
OPTIMIZE, REPAIR, TRUNCATE, LOCK, RENAME, ALTER and DROP TABLE
now issues an error of ER_NO_SUCH_TABLE when called with and FTS
index.