Add avx instruction set option for compiling php and workaround gmp download freeze in russia

[fwflunky]

With -mavx option php works faster than with -f option. Tested with simple bench script and multitime tool. (200 times)

Also i wrote workaround for libgmp, because gmplib.org blocked in russia
https://github.com/carbontwelve/php-performance-benchmark/blob/master/bench.php

[dktapps]

GMP is needed by the PM core, you can't just remove it. We're looking at setting up a PMMP mirror. gmplib.org got DoSed by GitHub Actions so it's also broken there.

AVX is not used because it's not supported by all target CPUs. If you want AVX support, your best bet is to use compile.sh directly on the target machine and omit the -t option, which will permit the script to use -march=native. However, beware that the resulting binary may not work on anything but the CPU it was built on.

In the future, please do not put multiple changes in one PR. Make a separate PR for each change you want to make.