Add aast_check to require explicit coeffect annotations on local functions
Summary:
This adds a parsing error similar to InferredLambdaContextInPoliciedLocalLintRuleTest.php to require developers to explicitly annotate closures within policied local contexts.
I'm fully aware that this is a bit of tech debt when combined with mchen110's work on coeffects_check.rs, but I didn't want to create a bunch of merge conflicts for a typechecker only check, so I added them here for now. I'll move them over to coeffects_check.rs once refactorings are a bit more stable.
Reviewed By: rodmk
Differential Revision:
D32307929
fbshipit-source-id:
dd3af4abda3ba66f4649817291a9641ee3a96398