Fix miscellaneous Clippy lints

crates/parser/src/grammar.rs

@@ -128,8 +128,7 @@ pub(crate) fn reparser(
         EXTERN_ITEM_LIST => items::extern_item_list,
         TOKEN_TREE if first_child? == T!['{'] => items::token_tree,
         ASSOC_ITEM_LIST => match parent? {
-            IMPL => items::assoc_item_list,
-            TRAIT => items::assoc_item_list,
+            IMPL | TRAIT => items::assoc_item_list,
             _ => return None,
         },
         ITEM_LIST => items::item_list,

crates/parser/src/grammar/expressions.rs

@@ -311,7 +311,7 @@ fn lhs(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)>
         _ => {
             // test full_range_expr
             // fn foo() { xs[..]; }
-            for &op in [T![..=], T![..]].iter() {
+            for op in [T![..=], T![..]] {
                 if p.at(op) {
                     m = p.start();
                     p.bump(op);

crates/parser/src/grammar/patterns.rs

@@ -73,7 +73,7 @@ fn pattern_single_r(p: &mut Parser, recovery_set: TokenSet) {
 
         // FIXME: support half_open_range_patterns (`..=2`),
         // exclusive_range_pattern (`..5`) with missing lhs
-        for &range_op in [T![...], T![..=], T![..]].iter() {
+        for range_op in [T![...], T![..=], T![..]] {
             if p.at(range_op) {
                 let m = lhs.precede(p);
                 p.bump(range_op);