using Foo as _

[oxinabox]

While we now have import Pipe as Pipe2 we don’t have using Pipe as Pipe2 but (#38521) will resolve that; so that it to bring into scope everything exported and rename the module itself.

In that context, it might also make sense to have using Pipe as _ to bring into scope everything exported but not bring the module name itself into scope.
Which would in particular fix the error related to using Pipe as the things it exports do not have name conflicts

[DilumAluthge]

Duplicate of #38521?

[oxinabox]

Cool, I have removed the part that overlaps