Part of https://github.com/astral-sh/ty/issues/159
Add support for adding a synthetic `typing.Self` type for `self`
arguments in methods.
`typing.Self` is assigned as the type if there are no annotations.
- Updated md tests.
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Co-authored-by: David Peter <mail@david-peter.de>
## Summary
- Type checkers (and type-checker authors) think in terms of types, but
I think most Python users think in terms of values. Rather than saying
that a _type_ `X` "has no attribute `foo`" (which I think sounds strange
to many users), say that "an object of type `X` has no attribute `foo`"
- Special-case certain types so that the diagnostic messages read more
like normal English: rather than saying "Type `<class 'Foo'>` has no
attribute `bar`" or "Object of type `<class 'Foo'>` has no attribute
`bar`", just say "Class `Foo` has no attribute `bar`"
## Test Plan
Mdtests and snapshots updated
