Support formatting for lazy_static::lazy_static!

[shulaoda]

closes #6287

Since this is special support for a specific crate macro, we should handle both forms — lazy_static! and lazy_static::lazy_static!.

[fee1-dead]

I think this is good to merge, @ytmimi thoughts?

[Manishearth]

This technically impacts formatted code. I don't know what our decision matrix is for stuff like this.

Also, at this point I don't know if we need to fix it, lazy_static is somewhat deprecated since there are equivalent stdlib types.

[ytmimi]

I think The changes to lazy_static::lazy_static! would need to be gated behind style_edition=2027.