style: Fix clippy warnings

Depends on D96634

Differential Revision: https://phabricator.services.mozilla.com/D96636

components/selectors/attr.rs

@@ -134,7 +134,7 @@ impl AttrSelectorOperator {
 }
 
 /// The definition of whitespace per CSS Selectors Level 3 § 4.
-pub static SELECTOR_WHITESPACE: &'static [char] = &[' ', '\t', '\n', '\r', '\x0C'];
+pub static SELECTOR_WHITESPACE: &[char] = &[' ', '\t', '\n', '\r', '\x0C'];
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq, ToShmem)]
 pub enum ParsedCaseSensitivity {

components/selectors/build.rs

@@ -27,7 +27,7 @@ fn main() {
 }
 
 /// <https://html.spec.whatwg.org/multipage/#selectors>
-static ASCII_CASE_INSENSITIVE_HTML_ATTRIBUTES: &'static str = r#"
+static ASCII_CASE_INSENSITIVE_HTML_ATTRIBUTES: &str = r#"
     accept
     accept-charset
     align

components/selectors/context.rs

@@ -286,6 +286,6 @@ where
     /// against.
     #[inline]
     pub fn shadow_host(&self) -> Option<OpaqueElement> {
-        self.current_host.clone()
+        self.current_host
     }
 }

components/selectors/matching.rs

@@ -334,10 +334,7 @@ where
     let result =
         matches_complex_selector_internal(iter, element, context, flags_setter, Rightmost::Yes);
 
-    match result {
-        SelectorMatchingResult::Matched => true,
-        _ => false,
-    }
+    matches!(result, SelectorMatchingResult::Matched)
 }
 
 #[inline]
@@ -915,9 +912,11 @@ where
             element,
             is_of_type,
             is_from_end,
-            cache.as_mut().map(|s| &mut **s),
+            cache.as_deref_mut(),
         );
-        cache.as_mut().map(|c| c.insert(element.opaque(), i));
+        if let Some(c) = cache.as_mut() { 
+            c.insert(element.opaque(), i) 
+        }
         i
     };
     debug_assert_eq!(

components/selectors/nth_index_cache.rs

@@ -37,7 +37,7 @@ pub struct NthIndexCacheInner(FxHashMap<OpaqueElement, i32>);
 impl NthIndexCacheInner {
     /// Does a lookup for a given element in the cache.
     pub fn lookup(&mut self, el: OpaqueElement) -> Option<i32> {
-        self.0.get(&el).map(|x| *x)
+        self.0.get(&el).copied()
     }
 
     /// Inserts an entry into the cache.

components/selectors/parser.rs

@@ -493,10 +493,8 @@ where
                 // :where and :is OR their selectors, so we can't put any hash
                 // in the filter if there's more than one selector, as that'd
                 // exclude elements that may match one of the other selectors.
-                if list.len() == 1 {
-                    if !collect_ancestor_hashes(list[0].iter(), quirks_mode, hashes, len) {
-                        return false;
-                    }
+                if list.len() == 1 && !collect_ancestor_hashes(list[0].iter(), quirks_mode, hashes, len) {
+                    return false;
                 }
                 continue;
             },
@@ -2777,8 +2775,8 @@ pub mod tests {
         assert!(list.is_ok());
     }
 
-    const MATHML: &'static str = "http://www.w3.org/1998/Math/MathML";
-    const SVG: &'static str = "http://www.w3.org/2000/svg";
+    const MATHML: &str = "http://www.w3.org/1998/Math/MathML";
+    const SVG: &str = "http://www.w3.org/2000/svg";
 
     #[test]
     fn test_parsing() {