Check for mysqldump test failed because of a difference in the
identifier names used in sys schema views before and after executing
the test. As part of the mysqldump test, sys schema is dumped to
a file then sys schema is dropped and recreated from the dump
file. While recreating the sys schema for few views, identifier
names used in view definition is stored differently. Hence check
of main.mysqldump test failed.

While preparing a view definition string, schema name is not
prefixed to the identifiers(using table alias name) for operation
as the SHOW CREATE VIEW(SQLCOM_SHOW_CREATE) and CREATE VIEW
(SQLCOM_CREATE_VIEW). While recreating a view, metadata of a
view(s) referencing the view being created/altered is updated.
LEX::sql_command in the scope of referencing view(s) metadata
update is set to SQLCOM_SHOW_FIELDS. Hence while preparing view
definition of referencing view(s) the schema name is prefixed
for identifier (using table alias name). So the difference in the
view definition is observed.

Currently mysql_register_view() is called with ALTER_VIEW mode
to update the referencing view's metadata. This method prepares
view TABLE_LIST object to create/alter a view. But while
updating referencing view's metadata, TABLE_LIST object
is prepared from the data-dictionary table. Hence re-preparing
TABLE_LIST object for the view in mysql_register_view() is not
necessary here. So to fix this issue, dd::update_view() is called
directly instead of mysql_register_view() to update referencing
view's metadata.

DDL operations on  TABLE or VIEW or Stored function might change
the referencing views "updatable" status. Hence even referencing
view's updatable state is checked and updated.

Change-Id: I8e03c7e5117a2c637ab14f761814ae8480114d08