RFR: 8298478: (fs) Path.of should allow input to include long path prefix [v4]

[Brian Burkhalter]

> Remove the long path `\?` or `\?\UNC` prefix before creating the `WindowsPath` instance..

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8298478: Improve conditional; align comment in test

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12423/files
  - new: https://git.openjdk.org/jdk/pull/12423/files/90ef2d30..f9de5966

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12423&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12423&range=02-03

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/12423.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12423/head:pull/12423

PR: https://git.openjdk.org/jdk/pull/12423