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_tables.inc

@@ -0,0 +1,20 @@
+--echo === information_schema.innodb_sys_tables  and innodb_sys_tablespaces ===
+--disable_query_log
+--replace_result  #P# #p#  #SP# #sp#
+--replace_regex /FTS_([0-9a-f_]+)([A-Z0-9_]+)/FTS_AUX_\2/
+
+SELECT t.name 'Table Name',
+	s.name 'Tablespace',
+	t.flag 'Table Flags',
+	t.n_cols 'Columns',
+	t.row_format 'Row Format',
+	t.zip_page_size 'Zip Size',
+	t.space_type 'Space Type'
+	FROM information_schema.innodb_sys_tables t LEFT JOIN
+	     information_schema.innodb_sys_tablespaces s
+	ON t.space = s.space
+	WHERE t.name not like 'SYS_%'
+	AND t.name NOT LIKE 'mysql/%'
+	AND t.name NOT LIKE 'sys/%'
+	ORDER BY t.name;
+--enable_query_log