Bug Fix (from Pylance): Allow non-identifier characters immediately after #region.

Bug Fix: Fixed a bug that led to a crash in certain circumstances where a TypedDict field annotation contained a circular reference to the TypedDict.

Bug Fix: Fixed a bug that led to a crash under certain circumstances when a dictionary expansion subexpression (**val) was used.

Bug Fix: Fixed a bug that resulted in incorrect type evaluation for a symbols within a py.typed module that is contained with a non-py.typed namespace package.

Bug Fix: Fixed inconsistency within isinstance type guard logic when handling the narrowing of a type that contains a union with Any or Unknown.

Bug Fix: Fixed a bug that resulted in a false positive error when generic class with an invariant type parameter is used in specialized form as a type argument for a class with a contravariant type parameter.

Performance: Improved type analysis performance in some cases that involve protocol matching where the protocol incorporates an overloaded method.

Bug Fix (contribution by André Fontenele): Fixed a bug that caused "go to definition" to go to a bogus position within a file in cases where the identifier refers to a module.

Performance: Added optimization to handle unions that contain large numbers of union literals.