RFR: 8239386: handle ContendedPaddingWidth in vm_version_aarch64

[Dan]

Handle ContendedPaddingWidth the same way other architectures do

Passes Hotspot Tier1

-------------

Commit messages:
 - 8239386: handle ContendedPaddingWidth in vm_version_aarch64

Changes: https://git.openjdk.java.net/jdk/pull/2814/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2814&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8239386
  Stats: 3 lines in 1 file changed: 3 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2814.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2814/head:pull/2814

PR: https://git.openjdk.java.net/jdk/pull/2814