RFR: 8255557: Decouple GCM from CipherCore [v2]

[Anthony Scarpino]

> Hi,
> 
> I need a review of this rather large change to GCM.  GCM will no longer use CipherCore, and AESCrypt  to handle it's buffers and other objects.  It is also a major code redesign limits the amount of data copies and make some performance-based decisions.
> 
> Thanks
> 
> Tony

Anthony Scarpino has updated the pull request incrementally with two additional commits since the last revision:

 - review comment updates
 - Fixed the lack of overlap detection with GCMEncrypt.update()

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4072/files
  - new: https://git.openjdk.java.net/jdk/pull/4072/files/f52d57d6..b21c2723

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4072&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4072&range=00-01

  Stats: 42 lines in 4 files changed: 10 ins; 23 del; 9 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4072.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4072/head:pull/4072

PR: https://git.openjdk.java.net/jdk/pull/4072