Rollup merge of #86277 - jsha:remove-must-use, r=Manishearth

Remove must_use from ALLOWED_ATTRIBUTES

This is a fairly common attribute on methods, but is not something you need to know when reading the method docs - the purpose of the attribute is for the compiler to tell you about it if you forget to use a value.

Removing reclaims some valuable space in the summary of methods, particularly when the attribute has a long string value.

As discussed in #84309. Partially addresses #81482.

r? ```@Manishearth```

Author: JohnTitor

src/librustdoc/html/render/mod.rs

@@ -965,14 +965,8 @@ fn render_assoc_item(
     }
 }
 
-const ALLOWED_ATTRIBUTES: &[Symbol] = &[
-    sym::export_name,
-    sym::link_section,
-    sym::must_use,
-    sym::no_mangle,
-    sym::repr,
-    sym::non_exhaustive,
-];
+const ALLOWED_ATTRIBUTES: &[Symbol] =
+    &[sym::export_name, sym::link_section, sym::no_mangle, sym::repr, sym::non_exhaustive];
 
 fn attributes(it: &clean::Item) -> Vec<String> {
     it.attrs

src/test/rustdoc/attributes.rs

@@ -8,14 +8,6 @@ pub extern "C" fn f() {}
 #[export_name = "bar"]
 pub extern "C" fn g() {}
 
-// @matches foo/enum.Foo.html '//*[@class="rust enum"]' \
-//      '#\[repr\(i64\)\]\n#\[must_use\]'
-#[repr(i64)]
-#[must_use]
-pub enum Foo {
-    Bar,
-}
-
 // @has foo/struct.Repr.html '//*[@class="docblock type-decl"]' '#[repr(C, align(8))]'
 #[repr(C, align(8))]
 pub struct Repr;

src/test/rustdoc/cap-lints.rs

@@ -3,8 +3,7 @@
 // therefore should not concern itself with the lints.
 #[deny(warnings)]
 
-// @has cap_lints/struct.Foo.html //pre '#[must_use]'
-#[must_use]
+// @has cap_lints/struct.Foo.html //* 'Struct Foo'
 pub struct Foo {
     field: i32,
 }