Loop over references to containers instead of using explicit iteration methods.

https://github.com/rust-lang-nursery/rust-clippy/wiki#explicit_iter_loop

lib/wasm/src/code_translator.rs

@@ -506,7 +506,7 @@ fn translate_operator(op: &Operator,
         Operator::BrTable { ref table } => {
             let (depths, default) = table.read_table();
             let mut min_depth = default;
-            for depth in depths.iter() {
+            for depth in &depths {
                 if *depth < min_depth {
                     min_depth = *depth;
                 }