[Wildcard Variables] implement THIS_ACCESS_FROM_FIELD_INITIALIZER

[pq]

The front-end has this error:

ThisAccessInFieldInitializer:
  problemMessage: "Can't access 'this' in a field initializer to read '#name'."
  analyzerCode: THIS_ACCESS_FROM_FIELD_INITIALIZER

that names THIS_ACCESS_FROM_FIELD_INITIALIZER (which doesn't exist).

That said, we do have IMPLICIT_THIS_REFERENCE_IN_INITIALIZER.

@kallentu: any reason we need a new error code here and can't use IMPLICIT_THIS_REFERENCE_IN_INITIALIZER?

Here's the relevant part of the spec:

https://github.com/dart-lang/language/blob/main/working/wildcards/feature-specification.md#initializing-formals

A corresponding (failing) test:

https://dart-ci.appspot.com/log/any/analyzer-asserts-linux/25960/language/wildcard_variables/initializing_formal_parameters/this_initializer_access_error_test

(There are co19 ones too.)

[dart-github-bot]

Summary: The issue requests the implementation of the THIS_ACCESS_FROM_FIELD_INITIALIZER lint rule, which would flag instances of accessing this within field initializers, potentially leading to unexpected behavior.

[pq]

Ok, after a nice ling chat w/ @stereotype441, I think I see what's happening.

TL;DR THIS_ACCESS_FROM_FIELD_INITIALIZER is likely a stale reference to an analyzer error code that existing pre CFE.

I'll loop back and do some cleanup but for now this whole issue is a bit of a red herring so I'll close it out.

Sorry for the noise!