This class originated in the very first commit of `rustdoc_ng`, and was used
to add a color border around the item decl based on its kind.
4fd061c426/src/rustdoc_ng/html/static/main.css (L102-L106)
The item decl no longer has a border, and there aren't any
kind-specific styles in modern rustdoc's rendering of this UI item.
Most of this commit is updating test cases so that they use `item-decl` to
find the `<pre>` tag instead of relying on the fact that the class name
had `rust {kind}` in it while other `<pre>` tags only had class `rust`.
rustdoc: remove unnecessary DOM class `h1.fqn`
It's misleading. The main heading sometimes isn't an fully qualified name at all.
It's also redundant. It's always a child of `div.main-heading`, so just use that.
It's misleading. The main heading sometimes isn't an fully qualified name at all.
It's also redundant. It's always a child of `div.main-heading`, so just use that.
