Auto merge of rust-lang#5798 - mikerite:fix-2277-2, r=yaahc

Add test for `needless_range_loop` issue

Closes rust-lang#2277

This was fixed when we fixed rust-lang#2542.

changelog: none

Author: bors

tests/ui/needless_range_loop2.rs

@@ -83,3 +83,13 @@ fn main() {
         println!("{}", arr[i]);
     }
 }
+
+mod issue2277 {
+    pub fn example(list: &[[f64; 3]]) {
+        let mut x: [f64; 3] = [10.; 3];
+
+        for i in 0..3 {
+            x[i] = list.iter().map(|item| item[i]).sum::<f64>();
+        }
+    }
+}