RFR: 8292158: AES-CTR cipher state corruption with AVX-512 [v2]

[AJ Ferguson]

> Fix cipher state corruption when encrypting/decrypting less than 16 bytes at a time.

AJ Ferguson has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:

 - Merge remote-tracking branch 'upstream/master' into aesctr-avx3
 - Add suggested changes
   
   Co-authored-by: smita-kamath <smita.kamath at intel.com>
 - exit preloop if len_reg is 0

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Changes: https://git.openjdk.org/jdk/pull/9635/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9635&range=01
  Stats: 4 lines in 1 file changed: 3 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/9635.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9635/head:pull/9635

PR: https://git.openjdk.org/jdk/pull/9635