Phobos Unittest

[Per Nordlöw]

On Saturday, 4 September 2021 at 12:40:02 UTC, Per Nordlöw wrote:
> then. I can make that refactoring in my favorite choice of 
> editor and see the result differ. In terms of binary size, and 
> speed and memory usage of check, build and link time.

Automated that is.

If we want this, shall we format as

```d
version (StdUnittest) [QUALIFIER...] unittest
```

instead of current

```d
version (StdUnittest)
[QUALIFIER...] unittest
```

?