Revert "Auto merge of #89709 - clemenswasser:apply_clippy_suggestions_2, r=petrochenkov"

The PR had some unforseen perf regressions that are not as easy to find.
Revert the PR for now.

This reverts commit 6ae8912a3e7d2c4c775024f58a7ba4b1aedc4073, reversing
changes made to 86d6d2b7389fe1b339402c1798edae8b695fc9ef.

13 files changed, 42 insertions, 29 deletions

diff --git a/compiler/rustc_data_structures/src/base_n.rs b/compiler/rustc_data_structures/src/base_n.rs
index 81e2501ecbe..3c7bea27124 100644
--- a/compiler/rustc_data_structures/src/base_n.rs
+++ b/compiler/rustc_data_structures/src/base_n.rs
@@ -14,7 +14,7 @@ const BASE_64: &[u8; MAX_BASE as usize] =
 
 #[inline]
 pub fn push_str(mut n: u128, base: usize, output: &mut String) {
-    debug_assert!((2..=MAX_BASE).contains(&base));
+    debug_assert!(base >= 2 && base <= MAX_BASE);
     let mut s = [0u8; 128];
     let mut index = 0;
 
diff --git a/compiler/rustc_data_structures/src/graph/implementation/mod.rs b/compiler/rustc_data_structures/src/graph/implementation/mod.rs
index 9ff401c3c7a..1aa7ac024d9 100644
--- a/compiler/rustc_data_structures/src/graph/implementation/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/implementation/mod.rs
@@ -206,11 +206,17 @@ impl<N: Debug, E: Debug> Graph<N, E> {
         AdjacentEdges { graph: self, direction, next: first_edge }
     }
 
-    pub fn successor_nodes(&self, source: NodeIndex) -> impl Iterator<Item = NodeIndex> + '_ {
+    pub fn successor_nodes<'a>(
+        &'a self,
+        source: NodeIndex,
+    ) -> impl Iterator<Item = NodeIndex> + 'a {
         self.outgoing_edges(source).targets()
     }
 
-    pub fn predecessor_nodes(&self, target: NodeIndex) -> impl Iterator<Item = NodeIndex> + '_ {
+    pub fn predecessor_nodes<'a>(
+        &'a self,
+        target: NodeIndex,
+    ) -> impl Iterator<Item = NodeIndex> + 'a {
         self.incoming_edges(target).sources()
     }
 
diff --git a/compiler/rustc_data_structures/src/graph/iterate/mod.rs b/compiler/rustc_data_structures/src/graph/iterate/mod.rs
index 1c6979dc489..a9db3497b23 100644
--- a/compiler/rustc_data_structures/src/graph/iterate/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/iterate/mod.rs
@@ -48,7 +48,7 @@ fn post_order_walk<G: DirectedGraph + WithSuccessors + WithNumNodes>(
         let node = frame.node;
         visited[node] = true;
 
-        for successor in frame.iter.by_ref() {
+        while let Some(successor) = frame.iter.next() {
             if !visited[successor] {
                 stack.push(PostOrderFrame { node: successor, iter: graph.successors(successor) });
                 continue 'recurse;
@@ -112,7 +112,7 @@ where
     /// This is equivalent to just invoke `next` repeatedly until
     /// you get a `None` result.
     pub fn complete_search(&mut self) {
-        for _ in self {}
+        while let Some(_) = self.next() {}
     }
 
     /// Returns true if node has been visited thus far.
diff --git a/compiler/rustc_data_structures/src/obligation_forest/mod.rs b/compiler/rustc_data_structures/src/obligation_forest/mod.rs
index caf515b0d19..25b7a84b3a0 100644
--- a/compiler/rustc_data_structures/src/obligation_forest/mod.rs
+++ b/compiler/rustc_data_structures/src/obligation_forest/mod.rs
@@ -390,7 +390,7 @@ impl<O: ForestObligation> ObligationForest<O> {
             .map(|(index, _node)| Error { error: error.clone(), backtrace: self.error_at(index) })
             .collect();
 
-        self.compress(|_| unreachable!());
+        self.compress(|_| assert!(false));
         errors
     }
 
@@ -612,7 +612,7 @@ impl<O: ForestObligation> ObligationForest<O> {
     fn compress(&mut self, mut outcome_cb: impl FnMut(&O)) {
         let orig_nodes_len = self.nodes.len();
         let mut node_rewrites: Vec<_> = std::mem::take(&mut self.reused_node_vec);
-        assert!(node_rewrites.is_empty());
+        debug_assert!(node_rewrites.is_empty());
         node_rewrites.extend(0..orig_nodes_len);
         let mut dead_nodes = 0;
 
@@ -623,13 +623,13 @@ impl<O: ForestObligation> ObligationForest<O> {
         //     self.nodes[0..index - dead_nodes] are the first remaining nodes
         //     self.nodes[index - dead_nodes..index] are all dead
         //     self.nodes[index..] are unchanged
-        for (index, node_rewrite) in node_rewrites.iter_mut().enumerate() {
+        for index in 0..orig_nodes_len {
             let node = &self.nodes[index];
             match node.state.get() {
                 NodeState::Pending | NodeState::Waiting => {
                     if dead_nodes > 0 {
                         self.nodes.swap(index, index - dead_nodes);
-                        *node_rewrite -= dead_nodes;
+                        node_rewrites[index] -= dead_nodes;
                     }
                 }
                 NodeState::Done => {
@@ -646,7 +646,7 @@ impl<O: ForestObligation> ObligationForest<O> {
                     }
                     // Extract the success stories.
                     outcome_cb(&node.obligation);
-                    *node_rewrite = orig_nodes_len;
+                    node_rewrites[index] = orig_nodes_len;
                     dead_nodes += 1;
                 }
                 NodeState::Error => {
@@ -655,7 +655,7 @@ impl<O: ForestObligation> ObligationForest<O> {
                     // check against.
                     self.active_cache.remove(&node.obligation.as_cache_key());
                     self.insert_into_error_cache(index);
-                    *node_rewrite = orig_nodes_len;
+                    node_rewrites[index] = orig_nodes_len;
                     dead_nodes += 1;
                 }
                 NodeState::Success => unreachable!(),
diff --git a/compiler/rustc_data_structures/src/sorted_map.rs b/compiler/rustc_data_structures/src/sorted_map.rs
index e80db0845a7..20e2a3b9696 100644
--- a/compiler/rustc_data_structures/src/sorted_map.rs
+++ b/compiler/rustc_data_structures/src/sorted_map.rs
@@ -205,10 +205,10 @@ impl<K: Ord, V> SortedMap<K, V> {
         R: RangeBounds<K>,
     {
         let start = match range.start_bound() {
-            Bound::Included(k) => match self.lookup_index_for(k) {
+            Bound::Included(ref k) => match self.lookup_index_for(k) {
                 Ok(index) | Err(index) => index,
             },
-            Bound::Excluded(k) => match self.lookup_index_for(k) {
+            Bound::Excluded(ref k) => match self.lookup_index_for(k) {
                 Ok(index) => index + 1,
                 Err(index) => index,
             },
@@ -216,11 +216,11 @@ impl<K: Ord, V> SortedMap<K, V> {
         };
 
         let end = match range.end_bound() {
-            Bound::Included(k) => match self.lookup_index_for(k) {
+            Bound::Included(ref k) => match self.lookup_index_for(k) {
                 Ok(index) => index + 1,
                 Err(index) => index,
             },
-            Bound::Excluded(k) => match self.lookup_index_for(k) {
+            Bound::Excluded(ref k) => match self.lookup_index_for(k) {
                 Ok(index) | Err(index) => index,
             },
             Bound::Unbounded => self.data.len(),
diff --git a/compiler/rustc_data_structures/src/sorted_map/index_map.rs b/compiler/rustc_data_structures/src/sorted_map/index_map.rs
index 1395bb16e87..e92db9ea128 100644
--- a/compiler/rustc_data_structures/src/sorted_map/index_map.rs
+++ b/compiler/rustc_data_structures/src/sorted_map/index_map.rs
@@ -75,7 +75,7 @@ impl<I: Idx, K: Ord, V> SortedIndexMultiMap<I, K, V> {
     ///
     /// If there are multiple items that are equivalent to `key`, they will be yielded in
     /// insertion order.
-    pub fn get_by_key(&self, key: K) -> impl Iterator<Item = &V> {
+    pub fn get_by_key(&'a self, key: K) -> impl 'a + Iterator<Item = &'a V> {
         self.get_by_key_enumerated(key).map(|(_, v)| v)
     }
 
@@ -84,7 +84,7 @@ impl<I: Idx, K: Ord, V> SortedIndexMultiMap<I, K, V> {
     ///
     /// If there are multiple items that are equivalent to `key`, they will be yielded in
     /// insertion order.
-    pub fn get_by_key_enumerated(&self, key: K) -> impl Iterator<Item = (I, &V)> {
+    pub fn get_by_key_enumerated(&'a self, key: K) -> impl '_ + Iterator<Item = (I, &V)> {
         let lower_bound = self.idx_sorted_by_item_key.partition_point(|&i| self.items[i].0 < key);
         self.idx_sorted_by_item_key[lower_bound..].iter().map_while(move |&i| {
             let (k, v) = &self.items[i];
diff --git a/compiler/rustc_data_structures/src/sso/map.rs b/compiler/rustc_data_structures/src/sso/map.rs
index d4274e99f1c..2de05cd4e56 100644
--- a/compiler/rustc_data_structures/src/sso/map.rs
+++ b/compiler/rustc_data_structures/src/sso/map.rs
@@ -257,7 +257,11 @@ impl<K: Eq + Hash, V> SsoHashMap<K, V> {
     pub fn remove(&mut self, key: &K) -> Option<V> {
         match self {
             SsoHashMap::Array(array) => {
-                array.iter().position(|(k, _v)| k == key).map(|index| array.swap_remove(index).1)
+                if let Some(index) = array.iter().position(|(k, _v)| k == key) {
+                    Some(array.swap_remove(index).1)
+                } else {
+                    None
+                }
             }
             SsoHashMap::Map(map) => map.remove(key),
         }
@@ -268,7 +272,11 @@ impl<K: Eq + Hash, V> SsoHashMap<K, V> {
     pub fn remove_entry(&mut self, key: &K) -> Option<(K, V)> {
         match self {
             SsoHashMap::Array(array) => {
-                array.iter().position(|(k, _v)| k == key).map(|index| array.swap_remove(index))
+                if let Some(index) = array.iter().position(|(k, _v)| k == key) {
+                    Some(array.swap_remove(index))
+                } else {
+                    None
+                }
             }
             SsoHashMap::Map(map) => map.remove_entry(key),
         }
@@ -415,14 +423,14 @@ impl<K, V> IntoIterator for SsoHashMap<K, V> {
 
 /// adapts Item of array reference iterator to Item of hashmap reference iterator.
 #[inline(always)]
-fn adapt_array_ref_it<K, V>(pair: &(K, V)) -> (&K, &V) {
+fn adapt_array_ref_it<K, V>(pair: &'a (K, V)) -> (&'a K, &'a V) {
     let (a, b) = pair;
     (a, b)
 }
 
 /// adapts Item of array mut reference iterator to Item of hashmap mut reference iterator.
 #[inline(always)]
-fn adapt_array_mut_it<K, V>(pair: &mut (K, V)) -> (&K, &mut V) {
+fn adapt_array_mut_it<K, V>(pair: &'a mut (K, V)) -> (&'a K, &'a mut V) {
     let (a, b) = pair;
     (a, b)
 }
diff --git a/compiler/rustc_data_structures/src/sso/set.rs b/compiler/rustc_data_structures/src/sso/set.rs
index f71522d3714..29baf4e1ddb 100644
--- a/compiler/rustc_data_structures/src/sso/set.rs
+++ b/compiler/rustc_data_structures/src/sso/set.rs
@@ -75,7 +75,7 @@ impl<T> SsoHashSet<T> {
     /// An iterator visiting all elements in arbitrary order.
     /// The iterator element type is `&'a T`.
     #[inline]
-    pub fn iter(&self) -> impl Iterator<Item = &T> {
+    pub fn iter(&'a self) -> impl Iterator<Item = &'a T> {
         self.into_iter()
     }
 
diff --git a/compiler/rustc_data_structures/src/stable_hasher.rs b/compiler/rustc_data_structures/src/stable_hasher.rs
index 2e992e76227..354f9dd93cc 100644
--- a/compiler/rustc_data_structures/src/stable_hasher.rs
+++ b/compiler/rustc_data_structures/src/stable_hasher.rs
@@ -229,14 +229,14 @@ impl<CTX> HashStable<CTX> for ::std::num::NonZeroUsize {
 
 impl<CTX> HashStable<CTX> for f32 {
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
-        let val: u32 = self.to_bits();
+        let val: u32 = unsafe { ::std::mem::transmute(*self) };
         val.hash_stable(ctx, hasher);
     }
 }
 
 impl<CTX> HashStable<CTX> for f64 {
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
-        let val: u64 = self.to_bits();
+        let val: u64 = unsafe { ::std::mem::transmute(*self) };
         val.hash_stable(ctx, hasher);
     }
 }
diff --git a/compiler/rustc_data_structures/src/stack.rs b/compiler/rustc_data_structures/src/stack.rs
index ba22c7f9b97..a4964b7aa0c 100644
--- a/compiler/rustc_data_structures/src/stack.rs
+++ b/compiler/rustc_data_structures/src/stack.rs
@@ -5,7 +5,6 @@ const RED_ZONE: usize = 100 * 1024; // 100k
 
 // Only the first stack that is pushed, grows exponentially (2^n * STACK_PER_RECURSION) from then
 // on. This flag has performance relevant characteristics. Don't set it too high.
-#[allow(clippy::identity_op)]
 const STACK_PER_RECURSION: usize = 1 * 1024 * 1024; // 1MB
 
 /// Grows the stack on demand to prevent stack overflow. Call this in strategic locations
diff --git a/compiler/rustc_data_structures/src/steal.rs b/compiler/rustc_data_structures/src/steal.rs
index a3ece655047..a1ffbae8b15 100644
--- a/compiler/rustc_data_structures/src/steal.rs
+++ b/compiler/rustc_data_structures/src/steal.rs
@@ -34,7 +34,7 @@ impl<T> Steal<T> {
     #[track_caller]
     pub fn borrow(&self) -> MappedReadGuard<'_, T> {
         let borrow = self.value.borrow();
-        if borrow.is_none() {
+        if let None = &*borrow {
             panic!("attempted to read from stolen value: {}", std::any::type_name::<T>());
         }
         ReadGuard::map(borrow, |opt| opt.as_ref().unwrap())
diff --git a/compiler/rustc_data_structures/src/tiny_list.rs b/compiler/rustc_data_structures/src/tiny_list.rs
index 9e605ea2d98..9b07f86846e 100644
--- a/compiler/rustc_data_structures/src/tiny_list.rs
+++ b/compiler/rustc_data_structures/src/tiny_list.rs
@@ -48,7 +48,7 @@ impl<T: PartialEq> TinyList<T> {
     #[inline]
     pub fn contains(&self, data: &T) -> bool {
         let mut elem = self.head.as_ref();
-        while let Some(e) = elem {
+        while let Some(ref e) = elem {
             if &e.data == data {
                 return true;
             }
diff --git a/compiler/rustc_data_structures/src/vec_linked_list.rs b/compiler/rustc_data_structures/src/vec_linked_list.rs
index ce60d40b24b..1cf030d852e 100644
--- a/compiler/rustc_data_structures/src/vec_linked_list.rs
+++ b/compiler/rustc_data_structures/src/vec_linked_list.rs
@@ -2,8 +2,8 @@ use rustc_index::vec::{Idx, IndexVec};
 
 pub fn iter<Ls>(
     first: Option<Ls::LinkIndex>,
-    links: &Ls,
-) -> impl Iterator<Item = Ls::LinkIndex> + '_
+    links: &'a Ls,
+) -> impl Iterator<Item = Ls::LinkIndex> + 'a
 where
     Ls: Links,
 {