Since a group GPBUnknownField uses a GPBUnknownFields and that is mutable, it needs to be copied so two instances aren't linked.
PiperOrigin-RevId: 663323972
Make a new internal api for collecting up the unknown group fields
that will be used in a future change.
Add testing for the new api and for unknown field parsing of groups in
general.
PiperOrigin-RevId: 654875605
Ensure all apis are called directly in tests.
Correct `GPBUnknownField` `-copy` to not have to make a new instance
since it is immutable in the new form.
PiperOrigin-RevId: 650690942
Port of the interesting `GPBUnknownFieldsSet` tests to `GPBUnknownFields`
as they provide coverage of general handing of unknown fields during parsing.
Also tweak the `Set` tests to actually use a registry to confirm behaviors around
extensions where the test previously wasn't as complete.
PiperOrigin-RevId: 650660181
`GPBUnknownFields` will be the eventually replacement for `GPBUnknownFieldSet`. This
introduces the type and the changes to `GPBUnknownField`.
The new api will preserve the wire ordering of unknown fields. This is now checked
in conformance tests.
While this adds the type changes and tests them, it does not yet wire the changes
in to the rest of the Runtime, so the conformance tests still done pass.
`GPBUnknownFieldSet` also hasn't been deprecated yet, that will come in later with
the wiring in to the runtime.
PiperOrigin-RevId: 648361455
Thomas Van Lenten