RFR: 8253821: Improve ByteBuffer performance with GCM

[Anthony Scarpino]

8253821: Improve ByteBuffer performance with GCM

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Commit messages:
 - comments, dead code, change maxlen tp 1k
 - remove debug line
 - removing comments and unused method
 - Moved into Git

Changes: https://git.openjdk.java.net/jdk/pull/411/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=411&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253821
  Stats: 842 lines in 11 files changed: 739 ins; 29 del; 74 mod
  Patch: https://git.openjdk.java.net/jdk/pull/411.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/411/head:pull/411

PR: https://git.openjdk.java.net/jdk/pull/411