RFR: 8355342: File.getCanonicalPath on Java 24 resolves paths on network drives to UNC format [v8]

[Brian Burkhalter]

> `File.getCanonicalPath` invokes `GetFinalPathNameByHandle` on the result of `canonicalize0` which causes the drive letter of a mapped drive to be converted to a UNC prefix. If such a substitution is detected, this request proposes to revert the conversion of drive letter to UNC prefix before returning the canonical path.

Brian Burkhalter has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 11 additional commits since the last revision:

 - 8355342: Derive final path only for reparse points
 - Merge
 - 8355342: Remove unused, vestigial code
 - 8355342: Do not check for backslash as third character of input pathname string
 - 8355342: Fall back to canonicalize0() result if drive letter converted to a long / UNC prefix
 - Merge
 - Merge
 - 8355342: Corrected a comment
 - 8355342: Add missing space in constant declaration
 - 8355342: Fix possible sneaky NullPointerException
 - ... and 1 more: https://git.openjdk.org/jdk/compare/253f1dfc...e4cad2b1

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Changes:
  - all: https://git.openjdk.org/jdk/pull/27324/files
  - new: https://git.openjdk.org/jdk/pull/27324/files/d88320a6..e4cad2b1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27324&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27324&range=06-07

  Stats: 35449 lines in 890 files changed: 19072 ins; 11590 del; 4787 mod
  Patch: https://git.openjdk.org/jdk/pull/27324.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27324/head:pull/27324

PR: https://git.openjdk.org/jdk/pull/27324