Add ngx-php to opcache supported sapis

[joanhey]

Now we are using the cli-server.
But it's time to use our name in the SAPI.

This SAPI embed PHP in Nginx server.
https://github.com/rryqszq4/ngx-php

And in the Techempower benchmarks, it's the fastest PHP SAPI. https://www.techempower.com/benchmarks/#section=data-r20

Thank you.

[joanhey]

Welcome any help to this SAPI :)

[joanhey]

Perhaps will be good to facilitate to new SAPIs, to use the OPcache.
Anyway any SAPI can use it, with the cli-server SAPI. We do it now, and also the php module in nginx-unit.

[iluuu1994]

In the future, it might make more sense for the SAPI to opt into opcache rather than opcache opting into SAPIs. But this looks ok to me for what we have now.

[dstogov]

hi @joanhey, I suspect ngx-php is not going to be fully compatible with opcache.
Do it run php code for different requests in context of a single multiplexing process?
In this case opcache itself won't make speed improvement, but it enables Optimizer and JIT that may help.

It's not a big problem to merge this commit, but it's better to implement @iluuu1994 idea (add some SAPI flag).

[joanhey]

It's multi-process and one thread in per-process, because nginx use multi-process . So php handle request one by one in pre-process of nginx.
So every ngx-php is a fork, and only process 1 req at a time.

But we can also include php files outside of the init worker, and without the OPcache the performance is not very good.

[joanhey]

This graph is without OPcache.
With opcache we have the same performance, with the code inline or included from file.