Fix #5761 by marking all `opcache_` functions as impure, as they are affected by runtime/engine (#5762)
Fix #5761 by marking all `opcache_` functions as impure, as they are affected by runtime/engine (#5762)

Quoting original issue (fixes #5761):

> Given this snippet ( https://psalm.dev/r/4d51eeab35 ):
>
> ```php
> <?php
>
> function invalidate_cache_for(string $path): void {
>     opcache_invalidate($path);
> }
>
> invalidate_cache_for('foo');
> ```
>
> Psalm reports the `opcache_invalidate()` call as `UnusedFunctionCall`. I'm wondering if `opcache_invalidate()` is perhaps inferred as a pure function? The only reference to it that I could find is in https://github.com/vimeo/psalm/blob/1a59e8180878cd7a1758e30c1558cd27e42f7478/dictionaries/CallMap.php, but no purity markers are there.
>
> I'd gladly fix these, if I could get a pointer to where purity is determined.
vimeo/psalm,vimeo/psalm