RFR: 8258576: Try to get zerobased CCS if heap is above 32 and CDS is disabled [v2]

[Richard Reingruber]

> Please review this small enhancement if CDS is disabled.
> 
> It tries to get a zerobased compressed class space if we have a not-zerobased compressed oops heap, i.e. the heap is above 32g. In this case there is a good chance to locate CCS below 32g.
> 
> The fix passed our CI testing: JCK and JTREG, also in Xcomp mode, SPECjvm2008, SPECjbb2015, Renaissance Suite,
> SAP specific tests with fastdebug and release builds on all platforms

Richard Reingruber has updated the pull request incrementally with one additional commit since the last revision:

  In largeHeapAbove32GTest we have a klass shift of 3 on OSX too.

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1815/files
  - new: https://git.openjdk.java.net/jdk/pull/1815/files/3932ea11..1f7195de

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1815&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1815&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1815.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1815/head:pull/1815

PR: https://git.openjdk.java.net/jdk/pull/1815