Reject programs that do a put outside of iterators.

Closes #774.

src/test/compile-fail/put-in-fn.rs

@@ -1,8 +1,8 @@
 // xfail-stage1
 // xfail-stage2
 // xfail-stage3
-// error-pattern: iterator function
+// error-pattern:put in non-iterator
 
 fn f() -> int { put 10; }
 
-fn main() { }
+fn main() { }