RFR: 8293810: Remove granting of RuntimePermission("stopThread") from tests

[Alan Bateman]

This is a test only change to remove the granting of RuntimePermission("stopThread") from the tests. With Thread.stop changed to throw UOE it means there is nothing that requires this permission.

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/10577/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10577&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293810
  Stats: 52 lines in 6 files changed: 0 ins; 51 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10577.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10577/head:pull/10577

PR: https://git.openjdk.org/jdk/pull/10577