Eliminate more unnecessary calls to .iter().

lib/cretonne/src/regalloc/liveness.rs

@@ -433,7 +433,7 @@ impl Liveness {
         assert!(self.ebb_args.is_empty());
 
         for ebb in func.layout.ebbs() {
-            for &arg in func.dfg.ebb_args(ebb).iter() {
+            for &arg in func.dfg.ebb_args(ebb) {
                 let affinity = self.ranges.get(arg).unwrap().affinity;
                 if affinity.is_none() {
                     continue;

lib/frontend/src/ssa.rs

@@ -421,7 +421,7 @@ where
         // `use_var`'s traversal won't revisit these predecesors.
         let mut preds = Vec::new();
         mem::swap(&mut preds, &mut self.predecessors_mut(dest_ebb));
-        for &(pred, last_inst) in preds.iter() {
+        for &(pred, last_inst) in &preds {
             // For each predecessor, we query what is the local SSA value corresponding
             // to var and we put it as an argument of the branch instruction.
             let (pred_val, mut local_side_effects) =

lib/wasm/tests/testsuite.rs

@@ -69,8 +69,8 @@ fn handle_module(path: PathBuf) -> Result<(), String> {
             }
         }
     };
-    for func in translation.functions.iter() {
-        let il = match *func {
+    for func in translation.functions {
+        let il = match func {
             FunctionTranslation::Import() => continue,
             FunctionTranslation::Code { ref il, .. } => il.clone(),
         };