Clean up unneeded '&'s.

cranelift/src/filetest/concurrent.rs

@@ -136,7 +136,7 @@ fn worker_thread(
                     }
                 });
 
-                if let &Err(ref msg) = &result {
+                if let Err(ref msg) = result {
                     dbg!("FAIL: {}", msg);
                 }
 

cranelift/src/filetest/domtree.rs

@@ -96,7 +96,7 @@ impl SubTest for TestDomtree {
         // Now we know that everything in `expected` is consistent with `domtree`.
         // All other EBB's should be either unreachable or the entry block.
         for ebb in func.layout.ebbs().skip(1).filter(
-            |ebb| !expected.contains_key(&ebb),
+            |ebb| !expected.contains_key(ebb),
         )
         {
             if let Some(got_inst) = domtree.idom(ebb) {

cranelift/src/filetest/subtest.rs

@@ -85,14 +85,14 @@ impl<'a> filecheck::VariableMap for Context<'a> {
 /// Run filecheck on `text`, using directives extracted from `context`.
 pub fn run_filecheck(text: &str, context: &Context) -> Result<()> {
     let checker = build_filechecker(context)?;
-    if checker.check(&text, context).map_err(
+    if checker.check(text, context).map_err(
         |e| format!("filecheck: {}", e),
     )?
     {
         Ok(())
     } else {
         // Filecheck mismatch. Emit an explanation as output.
-        let (_, explain) = checker.explain(&text, context).map_err(
+        let (_, explain) = checker.explain(text, context).map_err(
             |e| format!("explain: {}", e),
         )?;
         Err(format!("filecheck failed:\n{}{}", checker, explain))