Auto merge of #79529 - Dylan-DPC:rollup-6k20msr, r=Dylan-DPC

Rollup of 11 pull requests

Successful merges:

 - #79327 (Require allocator to be static for boxed `Pin`-API)
 - #79340 (Rename "stability" CSS class to "item-info" and combine `document_stability` with `document_short`)
 - #79363 (BTreeMap: try to enhance various comments)
 - #79395 (Move ui if tests from top-level into `expr/if`)
 - #79443 (Improve rustdoc JS tests error output)
 - #79464 (Extend doc keyword feature by allowing any ident)
 - #79484 (add enable-full-tools to freebsd builds to prevent occasional link er…)
 - #79505 (Cleanup: shorter and faster code)
 - #79514 (Add test for issue #54121: order dependent trait bounds)
 - #79516 (Remove unnecessary `mut` binding)
 - #79528 (Fix a bootstrap comment)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_lint/src/nonstandard_style.rs

@@ -94,9 +94,9 @@ fn to_camel_case(s: &str) -> String {
                 }
 
                 if new_word {
-                    camel_cased_component.push_str(&c.to_uppercase().to_string());
+                    camel_cased_component.extend(c.to_uppercase());
                 } else {
-                    camel_cased_component.push_str(&c.to_lowercase().to_string());
+                    camel_cased_component.extend(c.to_lowercase());
                 }
 
                 prev_is_lower_case = c.is_lowercase();

compiler/rustc_span/src/symbol.rs

@@ -1590,11 +1590,6 @@ impl Symbol {
         self == kw::Try
     }
 
-    /// Used for sanity checking rustdoc keyword sections.
-    pub fn is_doc_keyword(self) -> bool {
-        self <= kw::Union
-    }
-
     /// A keyword or reserved identifier that can be used as a path segment.
     pub fn is_path_segment_keyword(self) -> bool {
         self == kw::Super