When checking is any of the renamed columns part of the
columns for new indexes we accessed NULL pointer if checked
column used on index was added on same statement. Additionally,
we tried to check too many indexes, added_index_count
is enough here.
MDEV-9469: 'Incorrect key file' on ALTER TABLE
InnoDB needs to rebuild table if column name is changed and
added index (or foreign key) is created based on this new
name in same alter table.
