RFR: 8288047: Accelerate Poly1305 on x86_64 using AVX512 instructions [v17]

[Volodymyr Paprotski]

> Handcrafted x86_64 asm for Poly1305. Main optimization is to process 16 message blocks at a time. For more details, left a lot of comments in `macroAssembler_x86_poly.cpp`.
> 
> - Added new KAT test for Poly1305 and a fuzz test to compare intrinsic and java.
>   - Would like to add an `InvalidKeyException` in `Poly1305.java` (see commented out block in that file), but that conflicts with the KAT. I do think we should detect (R==0 || S ==0) so would like advice please.
> - Added a JMH perf test.
>    - JMH test had to use reflection (instead of existing `MacBench.java`), since Poly1305 is not 'properly' registered with the provider.
> 
> Perf before:
> 
> Benchmark                   (dataSize)  (provider)   Mode  Cnt        Score        Error  Units
> Poly1305DigestBench.digest          64              thrpt    8  2961300.661 ± 110554.162  ops/s
> Poly1305DigestBench.digest         256              thrpt    8  1791912.962 ±  86696.037  ops/s
> Poly1305DigestBench.digest        1024              thrpt    8   637413.054 ±  14074.655  ops/s
> Poly1305DigestBench.digest       16384              thrpt    8    48762.991 ±    390.921  ops/s
> Poly1305DigestBench.digest     1048576              thrpt    8      769.872 ±      1.402  ops/s
> 
> and after:
> 
> Benchmark                   (dataSize)  (provider)   Mode  Cnt        Score        Error  Units
> Poly1305DigestBench.digest          64              thrpt    8  2841243.668 ± 154528.057  ops/s
> Poly1305DigestBench.digest         256              thrpt    8  1662003.873 ±  95253.445  ops/s
> Poly1305DigestBench.digest        1024              thrpt    8  1770028.718 ± 100847.766  ops/s
> Poly1305DigestBench.digest       16384              thrpt    8   765547.287 ±  25883.825  ops/s
> Poly1305DigestBench.digest     1048576              thrpt    8    14508.458 ±     56.147  ops/s

Volodymyr Paprotski has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 25 commits:

 - Vladimir's review comments
 - Merge remote-tracking branch 'origin/master' into avx512-poly
 - Merge remote-tracking branch 'origin/master' into avx512-poly
 - Vladimir's review
 - live review with Sandhya
 - jcheck
 - Sandhya's review
 - fix windows and 32b linux builds
 - add getLimbs to interface and reviews
 - fix 32-bit build
 - ... and 15 more: https://git.openjdk.org/jdk/compare/7357a1a3...8f5942d9

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

Changes: https://git.openjdk.org/jdk/pull/10582/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10582&range=16
  Stats: 1859 lines in 32 files changed: 1823 ins; 3 del; 33 mod
  Patch: https://git.openjdk.org/jdk/pull/10582.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10582/head:pull/10582

PR: https://git.openjdk.org/jdk/pull/10582