rustdoc should show pub use statements

[thestinger]

They're part of the public API, so it would be nice if they showed up.

It would make http://static.rust-lang.org/doc/core/prelude.html show what's in the prelude for example.

[metajack]

nominating for feature complete

[graydon]

accepted for feature-complete milestone

[huonw]

@cmr, does this happen in rustdoc_ng?

[emberian]

#8125

/cc @Seldaek

@huonw It's the last remaining feature.

[Seldaek]

Done!

[emberian]

Now that rustdoc_ng has been merged, closing.