MDEV-11426 Remove InnoDB INFORMATION_SCHEMA.FILES implementation

MySQL 5.7 introduced WL#7943: InnoDB: Implement Information_Schema.Files
to provide a long-term alternative for accessing tablespace metadata.
The INFORMATION_SCHEMA.INNODB_* views are considered internal interfaces
that are subject to change or removal between releases. So, users should
refer to I_S.FILES instead of I_S.INNODB_SYS_TABLESPACES to fetch metadata
about CREATE TABLESPACE.

Because MariaDB 10.2 does not support CREATE TABLESPACE or
CREATE TABLE…TABLESPACE for InnoDB, it does not make sense to support
I_S.FILES either. So, let MariaDB 10.2 omit the code that was added in
MySQL 5.7. After this change, I_S.FILES will report the empty result,
unless some other storage engine in MariaDB 10.2 implements the interface.
(The I_S.FILES interface was originally created for the NDB Cluster.)

mysql-test/suite/innodb/include/show_i_s_tablespaces.inc

@@ -17,22 +17,4 @@ SELECT s.name 'Space_Name',
 	AND s.name NOT LIKE 'mysql/%'
 	AND s.name NOT LIKE 'sys/%'
 	ORDER BY s.space;
-
-# This SELECT will not show UNDO or TEMPORARY tablespaces since
-# they are only in FILES, not SYS_TABLESPACES.
---echo === information_schema.files ===
---replace_regex  /innodb_file_per_table.[0-9]+/innodb_file_per_table.##/   /#P#/#p#/  /#SP#/#sp#/
---replace_result ./ MYSQLD_DATADIR/  $MYSQLD_DATADIR/ MYSQLD_DATADIR/  $MYSQLD_DATADIR MYSQLD_DATADIR/  $MYSQL_TMP_DIR MYSQL_TMP_DIR  $INNODB_PAGE_SIZE DEFAULT
-SELECT 	s.name 'Space_Name',
-	f.file_type 'File_Type',
-	f.engine 'Engine',
-	f.status 'Status',
-	f.tablespace_name 'Tablespace_Name',
-	f.file_name 'Path'
-	FROM information_schema.files f,
-	     information_schema.innodb_sys_tablespaces s
-	WHERE f.file_id = s.space
-	AND s.name NOT LIKE 'mysql/%'
-	AND s.name NOT LIKE 'sys/%'
-	ORDER BY f.file_id;
 --enable_query_log