RFR: 8114830: (fs) Files.copy fails due to interference from something else changing the file system [v4]

[Brian Burkhalter]

> Throw a `FileSystemException` if attempting to create the target file with `O_EXCL` fails with `EEXIST`.

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

  8114830: Add flags.replaceExisting to check for FileSystemException

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/15141/files
  - new: https://git.openjdk.org/jdk/pull/15141/files/171fbd20..bc43e5eb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15141&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15141&range=02-03

  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/15141.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15141/head:pull/15141

PR: https://git.openjdk.org/jdk/pull/15141