Fix stream includes throwing errors during global state preservation

Related to issue #1308.

I wasn't sure exactly where to write tests for this. Any guidance would be appreciated!
`$matches` is unused.  Why case-insensitive?  phpvfs seems to use a hex/base64-alike suffix.

I'd go with a more explicit match:

```php
if (preg_match('/^vfs:|^phpvfs[a-z0-9]+:/', $file)) {
```