RFR: 8286771: workaround implemented for JDK-8282607 is incomplete

[Doug Simon]

Completes the workaround implemented in [JDK-8282607](https://bugs.openjdk.java.net/browse/JDK-8282607) so that the test actually passes when hs-err truncation is seen.

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Commit messages:
 - test must pass when hs-err truncation detected

Changes: https://git.openjdk.java.net/jdk/pull/8713/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8713&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8286771
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8713.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8713/head:pull/8713

PR: https://git.openjdk.java.net/jdk/pull/8713