[red-knot] defer annotation resolution when __future__.annotations is active

[MichaReiser]

Red-knot panics on this:

class IndexingMixin:
    def iloc(self) -> _iLocIndexer:
        return True


@doc(IndexingMixin.iloc)
class _iLocIndexer:
    pass

Changing the return type of IndexingMixing.iloc or changing the _iLocIndexer decorator to not reference IndexingMixing.iloc removes the panic

Source: https://github.com/pandas-dev/pandas/blob/0c24b20bd9cd743bd5f5afceb1a6fef54a2dbdc1/pandas/core/indexing.py#L4

[carljm]

We have support now for deferring resolution of annotations, which is the first part of fixing this. The second part is to extend that support to any module where from __future__ import annotations is active; currently it only applies in a stub file.

[carljm]

Confirmed that the above panic no longer occurs checking pandas. There is one other panic which is a shallow bug in with-item handling, I'll push a fix for it shortly.

[carljm]

With this fix and #13409 we can check pandas with no panic.

[charliermarsh]

Sweet