Apparently `path/posix` and `path/win32` have circular exports. I do not
know why.
Additionally there's a deprecated function `_makeLong` which is just
`toNamespacedPath`
- preserve referential invariants (e.g. path.posix === posix)
- remove glob and separator exports
- save removal of fromFileUrl and toFileUrl for a different PR as that
refactor is more involved
- addresses #18177