A class field typed AbortController or AbortSignal (plain, optional,
nullable, or in an array) maps to checked-dynamic storage, and the
class-field rule refused it (SC1090) although the same handles already
live in locals, Map values, and closures. They now take the checked-dynamic
slot, like the fetch Headers, Request, and Response handles.
controller?.abort() on a nullable controller was refused as a method call
(also for locals): the static abort lowering ran only without an optional
chain. It now runs again once the chain has narrowed the receiver.
Found by pi's TUI Editor (autocompleteAbort: AbortController | undefined).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>