Enable and fix several more clippy lints.

lib/codegen/src/bforest/map.rs

@@ -45,8 +45,8 @@ where
     C: Comparator<K>,
 {
     /// Create a new empty forest.
-    pub fn new() -> MapForest<K, V, C> {
-        MapForest { nodes: NodePool::new() }
+    pub fn new() -> Self {
+        Self { nodes: NodePool::new() }
     }
 
     /// Clear all maps in the forest.
@@ -83,8 +83,8 @@ where
     C: Comparator<K>,
 {
     /// Make an empty map.
-    pub fn new() -> Map<K, V, C> {
-        Map {
+    pub fn new() -> Self {
+        Self {
             root: None.into(),
             unused: PhantomData,
         }

lib/codegen/src/bforest/node.rs

@@ -73,7 +73,7 @@ impl<F: Forest> NodeData<F> {
     }
 
     /// Create an inner node with a single key and two sub-trees.
-    pub fn inner(left: Node, key: F::Key, right: Node) -> NodeData<F> {
+    pub fn inner(left: Node, key: F::Key, right: Node) -> Self {
         // Splat the key and right node to the whole array.
         // Saves us from inventing a default/reserved value.
         let mut tree = [right; INNER_SIZE];
@@ -86,7 +86,7 @@ impl<F: Forest> NodeData<F> {
     }
 
     /// Create a leaf node with a single key-value pair.
-    pub fn leaf(key: F::Key, value: F::Value) -> NodeData<F> {
+    pub fn leaf(key: F::Key, value: F::Value) -> Self {
         NodeData::Leaf {
             size: 1,
             keys: F::splat_key(key),
@@ -360,7 +360,7 @@ impl<F: Forest> NodeData<F> {
     ///
     /// In the first case, `None` is returned. In the second case, the new critical key for the
     /// right sibling node is returned.
-    pub fn balance(&mut self, crit_key: F::Key, rhs: &mut NodeData<F>) -> Option<F::Key> {
+    pub fn balance(&mut self, crit_key: F::Key, rhs: &mut Self) -> Option<F::Key> {
         match (self, rhs) {
             (&mut NodeData::Inner {
                  size: ref mut l_size,
@@ -514,7 +514,7 @@ pub(super) enum Removed {
 
 impl Removed {
     /// Create a `Removed` status from a size and capacity.
-    fn new(removed: usize, new_size: usize, capacity: usize) -> Removed {
+    fn new(removed: usize, new_size: usize, capacity: usize) -> Self {
         if 2 * new_size >= capacity {
             if removed == new_size {
                 Removed::Rightmost

lib/codegen/src/bforest/path.rs

@@ -22,8 +22,8 @@ pub(super) struct Path<F: Forest> {
 }
 
 impl<F: Forest> Default for Path<F> {
-    fn default() -> Path<F> {
-        Path {
+    fn default() -> Self {
+        Self {
             size: 0,
             node: [Node(0); MAX_PATH],
             entry: [0; MAX_PATH],

lib/codegen/src/bforest/pool.rs

@@ -12,8 +12,8 @@ pub(super) struct NodePool<F: Forest> {
 
 impl<F: Forest> NodePool<F> {
     /// Allocate a new empty pool of nodes.
-    pub fn new() -> NodePool<F> {
-        NodePool {
+    pub fn new() -> Self {
+        Self {
             nodes: PrimaryMap::new(),
             freelist: None,
         }

lib/codegen/src/bforest/set.rs

@@ -42,8 +42,8 @@ where
     C: Comparator<K>,
 {
     /// Create a new empty forest.
-    pub fn new() -> SetForest<K, C> {
-        SetForest { nodes: NodePool::new() }
+    pub fn new() -> Self {
+        Self { nodes: NodePool::new() }
     }
 
     /// Clear all sets in the forest.
@@ -78,8 +78,8 @@ where
     C: Comparator<K>,
 {
     /// Make an empty set.
-    pub fn new() -> Set<K, C> {
-        Set {
+    pub fn new() -> Self {
+        Self {
             root: None.into(),
             unused: PhantomData,
         }