Rollup merge of #87178 - moxian:rd-use, r=jyn514

[rustdoc] Copy only item path to clipboard rather than full `use` statement.

The (somewhat) recent addition of the "copy item import to clipboard" button is extremely nice.

However, i tend to write my code with fully qualified paths wherever feasible and only resort to `use` statements as a refactoring pass. This makes the "copy to clipboard" workflow awkward to use, as i would be copy-pasting that as, say

```rust
impl use std::ops::Add; for MyType {
```

and then go back  and remove the `use ` and `;`.

This PR removes the `use ;` decorations, making it much nicer to use for fully-qualified items. I argue, however, that this does not noticeably degrade experience for those who prefer to import items, since the hard part about those is getting the path right, and writing the `use ;` decoration can be done by hand with little effort.

src/librustdoc/html/static/js/main.js

@@ -986,7 +986,7 @@ function hideThemeButtonState() {
         });
 
         var el = document.createElement('textarea');
-        el.value = 'use ' + path.join('::') + ';';
+        el.value = path.join('::');
         el.setAttribute('readonly', '');
         // To not make it appear on the screen.
         el.style.position = 'absolute';