Rustdoc doesn't use re-exported type aliases in function signatures

[fleabitdev]

The glsp crate publicly re-exports everything from the glsp_engine crate:

//in lib.rs for the glsp crate
pub use glsp_engine::*;

The root of the glsp_engine crate defines a type alias, GResult. (This type alias is actually re-exported from a private module within the glsp_engine crate, but if I replace it with an inline definition, the bug doesn't change.)

//in lib.rs for the glsp_engine crate
type GResult<T> = Result<T, GError>;

When documenting the glsp_engine crate directly, Rustdoc will correctly document functions with a GResult return value.

However, when those functions are re-exported by the glsp crate, although the type alias itself is defined, the type alias is missing from function signatures.

[GuillaumeGomez]

It's a duplicate of #15823 so closing.