<i18n dev> RFR: 8253208: Move CDS related code to a separate class

[Yumin Qi]

With more CDS related code added to VM, it is time to move CDS code to a separate class. CDS is the new class which is
specific to CDS.

Tests: tier1-4

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

Commit messages:
 - 8253208: Move CDS related code to a separate class
 - Merge branch 'master' of https://github.com/yminqi/jdk into jdk-8253208
 - Merge remote-tracking branch 'origin/jdk-8252689'
 - 8252689: Classes are loaded from jrt:/java.base even when CDS is used
 - 8252689: Classes are loaded from jrt:/java.base even when CDS is used
 - 8252689: Classes are loaded from jrt:/java.base even when CDS is used

Changes: https://git.openjdk.java.net/jdk/pull/261/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=261&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253208
  Stats: 196 lines in 20 files changed: 110 ins; 53 del; 33 mod
  Patch: https://git.openjdk.java.net/jdk/pull/261.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/261/head:pull/261

PR: https://git.openjdk.java.net/jdk/pull/261