RFR: 8315960: test/jdk/java/io/File/TempDirDoesNotExist.java leaves test files behind [v6]

[Brian Burkhalter]

> Add a `finally` block to delete the created files.

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

  8315960: Rename MethodSources; use Stream.toList; check value returned by file deletion

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15757/files
  - new: https://git.openjdk.org/jdk/pull/15757/files/cab8fa50..50411b85

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15757&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15757&range=04-05

  Stats: 11 lines in 1 file changed: 2 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/15757.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15757/head:pull/15757

PR: https://git.openjdk.org/jdk/pull/15757