@FfiNative<Handle Function()>('doesntmatter')
external String? doesntmatter();

https://dart-review.googlesource.com/c/sdk/+/252601/6/pkg/vm/testcases/transformations/ffi/ffinative.dart

asFunction and lookupFunction do not allow the return type to be sticter than Object when the native type is Handle.

The old natives do allow the return type to be stricter than Object.

It would be good to update FfiNatives to be consistent with asFunction, but that would make them inconsistent with old natives.