RFR: 8290316: Ensure that all directory streams are closed in java.base [v3]

[Ryan Ernst]

> This commit guards uses of Files methods returning path streams in
> java.base to use try-with-resources.

Ryan Ernst has updated the pull request incrementally with one additional commit since the last revision:

  fix compile and address more feedback

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Changes:
  - all: https://git.openjdk.org/jdk/pull/9518/files
  - new: https://git.openjdk.org/jdk/pull/9518/files/c0a09f91..b5076b1a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9518&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9518&range=01-02

  Stats: 4 lines in 2 files changed: 1 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/9518.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9518/head:pull/9518

PR: https://git.openjdk.org/jdk/pull/9518