innodb_page_size=64k must reject ROW_FORMAT=REDUNDANT records longer than 16383 bytes

In all InnoDB row formats, the pointers or lengths stored in the record header can be at most 14 bits, that is, count up to 16383.
In ROW_FORMAT=REDUNDANT, this limits the maximum possible record length to 16383 bytes. In other ROW_FORMAT, it could merely limit the maximum length of variable-length fields.

When MySQL 5.7 introduced innodb_page_size=32k and 64k, the maximum record length was limited to 16383 bytes (I hope 16383, not 16384, to be able to distinguish from a record whose length is 0 bytes). This change is present in MariaDB Server 10.2.

We should fix MariaDB Server 10.1 accordingly.
There already is a test for this: innodb.innodb-64k