Add iter macro test for miri

Author: eholk

src/tools/miri/tests/pass/iter_macro.rs

@@ -0,0 +1,22 @@
+#![feature(iter_macro, yield_expr)]
+
+use std::iter::iter;
+
+fn main() {
+    let i = iter! { || {
+        yield 0;
+        for x in 5..10 {
+            yield x * 2;
+        }
+    } };
+    let mut i = i();
+    assert_eq!(i.next(), Some(0));
+    assert_eq!(i.next(), Some(10));
+    assert_eq!(i.next(), Some(12));
+    assert_eq!(i.next(), Some(14));
+    assert_eq!(i.next(), Some(16));
+    assert_eq!(i.next(), Some(18));
+    assert_eq!(i.next(), None);
+    assert_eq!(i.next(), None);
+    assert_eq!(i.next(), None);
+}