[Issue 22193] is expression not understanding global scope operator

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=22193

--- Comment #1 from João Lourenço <jlourenco5691 at gmail.com> ---
Adding a workaround that involves creating a new alias:

```
struct Foo(FooT) if (is(FooT == F!T, alias F = .FooT, T)) {}
```

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