Clean up examples

Author: g2p

examples/mandelbrot.rs

@@ -1,4 +1,4 @@
-#![feature(step_by, test)]
+#![feature(iterator_step_by, test)]
 
 extern crate test;
 extern crate simd;

examples/matrix-inverse.rs

@@ -25,6 +25,7 @@ fn mul(x: &[f32x4; 4], y: &[f32x4; 4]) -> [f32x4; 4] {
      ]
 }
 
+#[allow(dead_code)]
 fn inverse_naive(x: &[[f32; 4]; 4]) -> [[f32; 4]; 4] {
     let mut t = [[0_f32; 4]; 4];
     for i in 0..4 {

examples/nbody-nosimd.rs

@@ -66,7 +66,7 @@ struct Planet {
 }
 
 fn advance(bodies: &mut [Planet;N_BODIES], dt: f64, steps: i32) {
-    for _ in (0..steps) {
+    for _ in 0..steps {
         let mut b_slice: &mut [_] = bodies;
         loop {
             let bi = match shift_mut_ref(&mut b_slice) {

examples/ops.rs

@@ -2,6 +2,7 @@ extern crate simd;
 
 use simd::*;
 
+#[allow(unused_variables)]
 fn main() {
     let x = i32x4::splat(1_i32);
     let y = -x;