[openssl/openssl] c95e20: Fix LLVM vs Apple LLVM version numbering confusion...

[Richard Levitte]

  Branch: refs/heads/openssl-3.0
  Home:   https://github.com/openssl/openssl
  Commit: c95e2030c34646176b4843b5f0f48720d896f427
      https://github.com/openssl/openssl/commit/c95e2030c34646176b4843b5f0f48720d896f427
  Author: Richard Levitte <levitte at openssl.org>
  Date:   2022-10-05 (Wed, 05 Oct 2022)

  Changed paths:
    M crypto/bn/asm/rsaz-avx512.pl

  Log Message:
  -----------
  Fix LLVM vs Apple LLVM version numbering confusion, for $avx512ifma

Apple LLVM has a different version numbering scheme than upstream LLVM.
That makes for quite a bit of confusion.

https://en.wikipedia.org/wiki/Xcode#Toolchain_versions to the rescue,
they have collected quite a lot of useful data.

This change is concentrated around the `$avx512ifma` flag

Fixes #16670 for OpenSSL 3.0

Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Matt Caswell <matt at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19352)