RFR: 8283610: runtime/Thread/StopAtExit.java failing in loom repo

[Daniel D.Daugherty]

A trivial fix to enable runtime/Thread/StopAtExit.java in the loom repo.

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Commit messages:
 - 8283610: runtime/Thread/StopAtExit.java failing in loom repo

Changes: https://git.openjdk.java.net/loom/pull/180/files
 Webrev: https://webrevs.openjdk.java.net/?repo=loom&pr=180&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283610
  Stats: 3 lines in 1 file changed: 0 ins; 3 del; 0 mod
  Patch: https://git.openjdk.java.net/loom/pull/180.diff
  Fetch: git fetch https://git.openjdk.java.net/loom pull/180/head:pull/180

PR: https://git.openjdk.java.net/loom/pull/180