RFR: 8268626: Remove native pre-jdk9 support for jtreg failure handler

[Leonid Mesnik]

jtreg failure handler uses native lib to implement getPid for preJDK9. Currently. it is not needed and might be removed.

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Commit messages:
 - native lib support removed.

Changes: https://git.openjdk.java.net/jdk/pull/4476/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4476&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8268626
  Stats: 100 lines in 4 files changed: 0 ins; 96 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4476.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4476/head:pull/4476

PR: https://git.openjdk.java.net/jdk/pull/4476