This fixes a bug in USM mode where the `close` map type modifer was
attached to some `map.info.op`'s corresponding to user-defined type
members while the parent type instance itself is not marked as `close`.
This fix ensures that if a parent record type map does not have the
'close' flag, it is cleared from its members as well, maintaining
consistency.
Gemini was used to create tests. AI generated test code was reviewed
line-by-line by me. Which were derived from a reproducer I was working
with to debug the issue.
Assisted-by: Gemini <gemini@google.com>