test/compile-fail: clarify bad-for-loop

There are two distinct kinds of bad-for-loops to check for with two
distinct error messages.  The current bad-for-loop.rs does not make this
clear, so rewrite it into bad-for-loop{,-2}.rs.  The two failing
prototypes are:

  fn quux(_: &fn(&int) -> int) -> bool { true }
  fn quux(_: &fn(&int) -> bool) -> () { }

Note that the second one runs fine in rust-0.6 (the latest release), and
only fails with a rust built from `incoming`.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>

src/test/compile-fail/bad-for-loop-2.rs

@@ -0,0 +1,15 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    fn quux(_: &fn(&int) -> bool) -> () { }
+    for quux |_| { } //~ ERROR expected `for` closure to return
+                     // `bool`, but found `()`
+}

src/test/compile-fail/bad-for-loop.rs

@@ -9,7 +9,8 @@
 // except according to those terms.
 
 fn main() {
-    fn baz(_x: &fn(y: int) -> int) {}
-    for baz |_e| { } //~ ERROR A `for` loop iterator should expect a closure that returns `bool`
-                     //~^ ERROR expected `for` closure to return `bool`
+    fn quux(_: &fn(&int) -> int) -> bool { true }
+    for quux |_| { } //~ ERROR A `for` loop iterator should expect a
+                     // closure that returns `bool`.  This iterator
+                     // expects a closure that returns `int`.
 }