[jdk11u-dev] RFR: 8213409: Refactor sun.text.IntHashtable:i18n shell tests to plain java tests

[Aleksey Shipilev]

Clean backport to match `11.0.13-oracle`.

Additional testing:
 - [x] Affected tests still pass

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

Commit messages:
 - Backport e048289d95294f0fb8f1607a120c04de33106000

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/242/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=242&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8213409
  Stats: 116 lines in 3 files changed: 30 ins; 82 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/242.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/242/head:pull/242

PR: https://git.openjdk.java.net/jdk11u-dev/pull/242