Fix fatal "Didn't find gc marker as expected" for types.
Imported from https://youtrack.roxen.com/issue/PIKE-26
Reported by @grubba
Blocking PIKE-20
All types didn't have markers at cleanup time.
Imported from https://youtrack.roxen.com/issue/PIKE-26
Reported by @grubba
Blocking PIKE-20
All types didn't have markers at cleanup time.