A field the calling class doesn't declare was read off any same-named
class elsewhere, never off the classes it extends. It is now looked up on
the calling class's base classes, each the class its subclass's file
imports or declares, and a same-named class elsewhere is read last, only
for a type the call's file imports or declares.
A type a file imports from a package outside the project now links to
nothing in the project, unless a project file declares the package with
`declare module`, Flow libdefs included: microsoft-authentication's
`TelemetryReporter` from `@vscode/extension-telemetry` reached another
extension's interface of that name.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
