intra-doc links to modules instead of primitives inside standard library

[tspiteri]

For example in the doc for str::len:

This length is in bytes, not chars or graphemes.

The char in the doc links to char/index.html instead of primitive.char.html.

Outside of the standard library, char links to the primitive, unless there is a use std::char; statement in which case it links to the module.

[GuillaumeGomez]

Therefore we should try to link to types before modules I assume? I'll see how it comes out.

[tspiteri]

Yes I think types should go before modules.

After all it's always possible to use [`char`][`std::char`] if you actually want to link to the std::char module using char as the link text.

[GuillaumeGomez]

Oh btw, you can force the resolution by adding the type before hand like method@len. I wonder if this is documented somewhere... Just like you can say it's a macro by ! at the end or a function by adding () at the end.

[GuillaumeGomez]

It comes from the compiler directly. We need to re-order how the items are resolved.

cc @rust-lang/compiler

[jyn514]

@GuillaumeGomez an alternative is to resolve in an empty module first and only then resolve in the current scope. This ambiguity is only possible for primitives, any other types will give a multiple definition error: https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=16d8de614c51403e2f8576f355ed6f9c. Since primitives are always in scope they will be the only thing in scope in the empty module (assuming there's no super, crate, or self keyword).