For silly reasons, pathlib's generic implementation of `walk()` currently
resides in `glob._Globber`. This commit moves it into
`pathlib._abc.PathBase.walk()` where it really belongs, and makes
`pathlib.Path.walk()` call `os.walk()`.
pathlib now treats "`.`" as a valid file extension (suffix). This brings
it in line with `os.path.splitext()`.
In the (private) pathlib ABCs, we add a new `ParserBase.splitext()` method
that splits a path into a `(root, ext)` pair, like `os.path.splitext()`.
This method is called by `PurePathBase.stem`, `suffix`, etc. In a future
version of pathlib, we might make these base classes public, and so users
will be able to define their own `splitext()` method to control file
extension splitting.
In `pathlib.PurePath` we add optimised `stem`, `suffix` and `suffixes`
properties that don't use `splitext()`, which avoids computing the path
base name twice.
Suppress all `OSError` exceptions from `pathlib.Path.exists()` and `is_*()`
rather than a selection of more common errors as we do presently. Also
adjust the implementations to call `os.path.exists()` etc, which are much
faster on Windows thanks to GH-101196.
Remove support for supplying additional positional arguments to
`PurePath.relative_to()` and `is_relative_to()`. This has been deprecated
since Python 3.12.
Barney Gale