RFR: 8260506: VersionHelper cleanup

[Claes Redestad]

Some small modernizations and cleanups that ultimately help startup of apps using JNDI/InitialContext

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Commit messages:
 - VersionHelper cleanup

Changes: https://git.openjdk.java.net/jdk/pull/2259/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2259&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8260506
  Stats: 30 lines in 1 file changed: 2 ins; 16 del; 12 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2259.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2259/head:pull/2259

PR: https://git.openjdk.java.net/jdk/pull/2259