I just made the upgrade from 3.6.3 to 3.8.6.
After running etc/upgrade/upgrade-mysql-schema.pl
I noticed that the CachedGroupMember table
collation is still latin1.
Looking in the upgrade-mysql-schema.pl file,
the CachedGroupMember table is missing in
the @tables array.
Even if this is, at the moment, no problem because
the table only contains integer columns,
you should fix this to avoid differences in the
database schema between fresh 3.8 installations
and pre 3.8 upgraded installations.