Fix clippy warnings.

This commit fixes the current set of (stable) clippy warnings in the repo.

cranelift/entity/src/lib.rs

@@ -32,10 +32,7 @@
 #![deny(missing_docs, trivial_numeric_casts, unused_extern_crates)]
 #![warn(unused_import_braces)]
 #![cfg_attr(feature = "clippy", plugin(clippy(conf_file = "../../clippy.toml")))]
-#![cfg_attr(
-    feature = "cargo-clippy",
-    allow(clippy::new_without_default, clippy::new_without_default_derive)
-)]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::new_without_default))]
 #![cfg_attr(
     feature = "cargo-clippy",
     warn(

cranelift/entity/src/packed_option.rs

@@ -67,7 +67,7 @@ impl<T: ReservedValue> PackedOption<T> {
 impl<T: ReservedValue> Default for PackedOption<T> {
     /// Create a default packed option representing `None`.
     fn default() -> Self {
-        PackedOption(T::reserved_value())
+        Self(T::reserved_value())
     }
 }
 
@@ -78,7 +78,7 @@ impl<T: ReservedValue> From<T> for PackedOption<T> {
             t != T::reserved_value(),
             "Can't make a PackedOption from the reserved value."
         );
-        PackedOption(t)
+        Self(t)
     }
 }
 

cranelift/entity/src/set.rs

@@ -126,8 +126,7 @@ where
             // `(i + 1) * 8` = Last bit in byte.
             // `last - byte.leading_zeros()` = last set bit in byte.
             // `as usize` won't ever truncate as the potential range is `0..=8`.
-            .map(|(i, byte)| ((i + 1) * 8) - byte.leading_zeros() as usize)
-            .unwrap_or(0);
+            .map_or(0, |(i, byte)| ((i + 1) * 8) - byte.leading_zeros() as usize);
 
         Some(K::new(last_index))
     }