RFR: 8325991: Accelerate Poly1305 on x86_64 using AVX2 instructions [v6]

[Srinivas Vamsi Parasa]

> The goal of this PR is to accelerate the Poly1305 algorithm using AVX2 instructions (including IFMA) for x86_64 CPUs.
> 
> This implementation is directly based on the AVX2 Poly1305 hash computation as implemented in Intel(R) Multi-Buffer Crypto for IPsec Library (url: https://github.com/intel/intel-ipsec-mb/blob/main/lib/avx2_t3/poly_fma_avx2.asm)

Srinivas Vamsi Parasa has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 20 commits:

 - fix merge issues with avx_ifma
 - Merge branch 'master' of https://git.openjdk.java.net/jdk into jdk_poly
 - removed unused merge, faster and, redundant mov
 - remove unused uniions and fix uses_vl
 - change overloaded C to use COEFF
 - update algo writeup for clarity
 - 8325991: Accelerate Poly1305 on x86_64 using AVX2 instructions
 - fix typos in algorithm
 - add pseudo code algorithm
 - remove comment
 - ... and 10 more: https://git.openjdk.org/jdk/compare/54f09d73...d16a3b0b

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Changes: https://git.openjdk.org/jdk/pull/17881/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17881&range=05
  Stats: 804 lines in 8 files changed: 795 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/17881.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17881/head:pull/17881

PR: https://git.openjdk.org/jdk/pull/17881