Analyzer and CFE disagree on the resolution of import prefixes that alias local names

[Markzipan]

Snippet:
main.dart:

import 'import.dart' as thing;

class Foo {
  List<thing.Type> field;
  thing() {}
}

import.dart:

class Type {}

Passes in the analyzer but errors in the CFE with:

main.dart:4:8: Error: 'thing.Type' can't be used as a type because 'thing' doesn't refer to an import prefix.
  List<thing.Type> field;
       ^^^^^^^^^^

What's our convention here? Following the analyzer's convention and using 'this' to refer to the local name would be the least breaking.

[eernstg]

We do not have separate namespaces for separate kinds of declarations (labels are special, everything else goes into the same namespace). The declaration of field is an instance member, so it's in the instance scope, and hence thing in thing.Type resolves to the other instance member called thing.

So the CFE is right.

This issue is already reported for the analyzer in #32248, so I'll close this one as a duplicate. I've added a comment about this issue on #32248.

@Markzipan, about dev-compiler-kernel-blocker: I think the right way ahead would be to mark #32248 as a blocker.