rustdoc: remove redundant item kind class from `.item-decl > pre`

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.

https://github.com/rust-lang/rust/blob/4fd061c426902b0904c65e64a3780b21f9ab3afb/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`.

1 files changed, 2 insertions, 2 deletions

diff --git a/tests/rustdoc/inline_cross/dyn_trait.rs b/tests/rustdoc/inline_cross/dyn_trait.rs
index fa760540e43..0da8bfc3a9a 100644
--- a/tests/rustdoc/inline_cross/dyn_trait.rs
+++ b/tests/rustdoc/inline_cross/dyn_trait.rs
@@ -22,10 +22,10 @@ pub use dyn_trait::Ty2;
 pub use dyn_trait::Ty3;
 
 // @has user/fn.func0.html
-// @has - '//pre[@class="rust fn"]' "func0(_: &dyn Fn())"
+// @has - '//div[@class="item-decl"]/pre[@class="rust"]' "func0(_: &dyn Fn())"
 // FIXME(fmease): Show placeholder-lifetime bound, render "func0(_: &(dyn Fn() + '_))"
 pub use dyn_trait::func0;
 
 // @has user/fn.func1.html
-// @has - '//pre[@class="rust fn"]' "func1<'func>(_: &(dyn Fn() + 'func))"
+// @has - '//div[@class="item-decl"]/pre[@class="rust"]' "func1<'func>(_: &(dyn Fn() + 'func))"
 pub use dyn_trait::func1;