RFR: 8268353: Test libsvml.so is and is not present in jdk image

[Paul Sandoz]

Test that when the jdk.incubator.vector module is present that libsvml.so is present, and test the opposite case.

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Commit messages:
 - Improve test.
 - Test for linux and windows
 - 8268353: Test libsvml.so is and is not present in jdk image

Changes: https://git.openjdk.java.net/jdk/pull/4421/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4421&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8268353
  Stats: 99 lines in 2 files changed: 96 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4421.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4421/head:pull/4421

PR: https://git.openjdk.java.net/jdk/pull/4421