RFR: 8355228: Improve runtime/CompressedOops/CompressedClassPointersEncodingScheme.java to support JDK build with -XX:+UseCompactObjectHeaders

[Leonid Mesnik]

Sometimes it is easier to test JDK by building it with
 -XX:+UseCompactObjectHeaders
enabled by default. So CDS archives are generated and all tests including flagless are executed.
The option is transparent fand all tests even flagless tests are expected to  pass.

The only test runtime/CompressedOops/CompressedClassPointersEncodingScheme.java
start failing because expects to be executed with -XX:-UseCompactObjectHeaders

Please, note that it is a not a bug, just RFE. Test works  correctly.   

The fix improves test  to support testing of JDK build with -XX:+UseCompactObjectHeaders.

Tested with JDK build with UseCompactObjectHeaders enabled by default.

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Commit messages:
 - 8355228: Improve runtime/CompressedOops/CompressedClassPointersEncodingScheme.java to support JDK build with -XX:+UseCompactObjectHeaders

Changes: https://git.openjdk.org/jdk/pull/24781/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24781&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8355228
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/24781.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24781/head:pull/24781

PR: https://git.openjdk.org/jdk/pull/24781