[openssl/openssl] bcb52b: Optimize chacha20 on aarch64 by SVE2

[pauli]

  Branch: refs/heads/master
  Home:   https://github.openssl.org/openssl/openssl
  Commit: bcb52bcc9f9c36a85d037976676fd5ca52f307cd
      https://github.openssl.org/openssl/openssl/commit/bcb52bcc9f9c36a85d037976676fd5ca52f307cd
  Author: Daniel Hu <Daniel.Hu at arm.com>
  Date:   2022-06-22 (Wed, 22 Jun 2022)

  Changed paths:
    M crypto/chacha/asm/chacha-armv8-sve.pl

  Log Message:
  -----------
  Optimize chacha20 on aarch64 by SVE2

This patch improves existing chacha20 SVE patch by using SVE2,
which is an optional architecture feature of aarch64, with XAR
instruction that can improve the performance of chacha20.

Signed-off-by: Daniel Hu <Daniel.Hu at arm.com>

Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18522)