RFR: 8327046: (fs) Files.walk should be clear that depth-first traversal is pre-order [v3]

[Pavel Rappo]

> Please review this clarification to the specification of the two overloads of `java.nio.file.Files.walk`. No tests are added, as I believe the existing `StreamTest.testWalk*` methods already test the order sufficiently. I also took this opportunity to fix a few minor typos.

Pavel Rappo has updated the pull request incrementally with one additional commit since the last revision:

  Respond to feedback

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18063/files
  - new: https://git.openjdk.org/jdk/pull/18063/files/4240524b..5ffccf38

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18063&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18063&range=01-02

  Stats: 8 lines in 1 file changed: 0 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/18063.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18063/head:pull/18063

PR: https://git.openjdk.org/jdk/pull/18063