Fix clippy warnings.

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

cranelift/reader/src/isaspec.rs

@@ -25,7 +25,7 @@ pub enum IsaSpec {
 impl IsaSpec {
     /// If the `IsaSpec` contains exactly 1 `TargetIsa` we return a reference to it
     pub fn unique_isa(&self) -> Option<&dyn TargetIsa> {
-        if let IsaSpec::Some(ref isa_vec) = *self {
+        if let Self::Some(ref isa_vec) = *self {
             if isa_vec.len() == 1 {
                 return Some(&*isa_vec[0]);
             }

cranelift/reader/src/lexer.rs

@@ -461,6 +461,7 @@ impl<'a> Lexer<'a> {
     /// Get the next token or a lexical error.
     ///
     /// Return None when the end of the source is encountered.
+    #[allow(clippy::cognitive_complexity)]
     pub fn next(&mut self) -> Option<Result<LocatedToken<'a>, LocatedError>> {
         loop {
             let loc = self.loc();

cranelift/reader/src/parser.rs

@@ -3291,6 +3291,9 @@ mod tests {
         let c = Parser::new("true false true false")
             .parse_literals_to_constant_data(B32X4)
             .unwrap();
-        assert_eq!(c.to_vec(), [1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0])
+        assert_eq!(
+            c.into_vec(),
+            [1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0]
+        )
     }
 }