RFR: 8273297: AES/GCM non-AVX512+VAES CPUs suffer after 8267125 [v3]

[Smita Kamath]

> Performance dropped up to 10% for 1k data after 8267125 for CPUs that do not support the new intrinsic. Tests run were crypto.full.AESGCMBench and crypto.full.AESGCMByteBuffer from the jmh micro benchmarks.
> 
> The problem is each instance of GHASH allocates 96 extra longs for the AVX512+VAES intrinsic regardless if the intrinsic is used. This extra table space should be allocated differently so that non-supporting CPUs do not suffer this penalty. This issue also affects non-Intel CPUs too.

Smita Kamath has updated the pull request incrementally with one additional commit since the last revision:

  Fixed length decrement issue

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5402/files
  - new: https://git.openjdk.java.net/jdk/pull/5402/files/7ea464ae..19b0d547

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5402&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5402&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5402.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5402/head:pull/5402

PR: https://git.openjdk.java.net/jdk/pull/5402