* Only inline public items when inlining glob imports.
* Never inline while in a private module or a child of a private module.
* Never inline impls. This allowed the removal of a workaround in the
rendering code.
Currently if a `#[doc(hidden)] pub use` item is inlined the `hidden`
attribute is ignored so the item can appear in the docs. By never inlining
such imports, they can be stripped.