RFR: 8224509: Incorrect alignment in CDS related allocation code on 32-bit platforms [v2]

[Calvin Cheung]

> CDS aligns pointers and sizes to BytesPerWord. On 64-bit, BytesPerWord = 8. On 32-bit, BytesPerWord = 4.
> 
> To make the alignment consistent between 64- and 32-bit platforms, this patch changes the alignment value to 8.
> 
> Testing: tiers 1 - 4
>                built linux-x86-debug.

Calvin Cheung has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev
excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since
the last revision:

 - Merge branch 'master' of github.com:calvinccheung/jdk into 8224509
 - set SharedSpaceObjectAlignment to KlassAlignmentInBytes
 - 8224509 (initial commit)

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/476/files
  - new: https://git.openjdk.java.net/jdk/pull/476/files/d17d328f..04b7a777

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=476&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=476&range=00-01

  Stats: 18819 lines in 2008 files changed: 6755 ins; 4065 del; 7999 mod
  Patch: https://git.openjdk.java.net/jdk/pull/476.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/476/head:pull/476

PR: https://git.openjdk.java.net/jdk/pull/476