[jdk8u-dev] RFR: 8287663: Add a regression test for JDK-8287073

[Severin Gehwolf]

Simple low risk backport for a regression check of https://bugs.openjdk.org/browse/JDK-8287073 (forthcoming). The only changes were (other than context changes due to `optResult.equals(Optional.empty()` vs `optResult.isEmpty()` differences):

- Bug line in test. Fixed manually
- `Files.writeString()` => `Files.write()` changes in test.

Testing:
 - [x] New regression test fails without the product fix of JDK-8287073, passes with it.
 - [x] Linux container tests on x86_64 and cg1

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Commit messages:
 - Backport 2d8c6490540e3ccea23b81129b2e4073915071e0

Changes: https://git.openjdk.org/jdk8u-dev/pull/323/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=323&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8287663
  Stats: 36 lines in 2 files changed: 35 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/323.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/323/head:pull/323

PR: https://git.openjdk.org/jdk8u-dev/pull/323