Native AOT for extensions

aweXpect reflects over a type only when it has no registration in TypeMetadataRegistry, and switches that fallback off when an application is published with trimming or Native AOT enabled, so that a comparison or recording never silently verifies less than it claims to (see Native AOT and trimming). An extension takes part in this in two ways.

An extension method whose argument reaches an equivalency comparison or an event recording only reveals an open type parameter at its own call site, so it has to carry the marker that lets the source generator register the type at the consumer's call site: [RequiresMemberMetadata] for a value that is compared, [RequiresEventMetadata] for a subject that is recorded:

using aweXpect.Core.Metadata;
using aweXpect.Recording;

public static IEventRecording<T> Watch<T>([RequiresEventMetadata] this T subject)
    where T : notnull
    => subject.Record().Events();

An extension that reflects over a subject itself should guard the reflection with ReflectionFallback.IsSupported and fail with a message that names the aweXpect.ReflectionFallback.IsSupported runtime switch otherwise, so that it behaves the same way as the built-in expectations.