Fallout to compile-fail tests.

This change is worrisome to me, both because:

1. I thought the rules in RFC 599 imply that the `Box<Trait>` without `'static`
   in the first case would expand to the second case, but their behaviors
   here differ.  And,

2. The explicit handling of `'static` should mean `dropck` has no application
   here and thus we should have seen no change to the expected error messages.
   Nonetheless, the error messages changed.

Author: pnkfelix

src/test/compile-fail/unboxed-closures-failed-recursive-fn-1.rs

@@ -22,12 +22,24 @@ fn a() {
     let mut factorial: Option<Box<Fn(u32) -> u32>> = None;
 
     let f = |x: u32| -> u32 {
+        //~^ ERROR `factorial` does not live long enough
+        let g = factorial.as_ref().unwrap();
+        if x == 0 {1} else {x * g(x-1)}
+    };
+
+    factorial = Some(Box::new(f));
+}
+
+fn b() {
+    let mut factorial: Option<Box<Fn(u32) -> u32 + 'static>> = None;
+
+    let f = |x: u32| -> u32 {
+        //~^ ERROR closure may outlive the current function, but it borrows `factorial`
         let g = factorial.as_ref().unwrap();
         if x == 0 {1} else {x * g(x-1)}
     };
 
     factorial = Some(Box::new(f));
-    //~^ ERROR cannot assign to `factorial` because it is borrowed
 }
 
 fn main() { }