move the signature into the closure type

src/test/compile-fail/closure-bounds-static-cant-capture-borrowed.rs

@@ -13,8 +13,7 @@ fn bar<F>(blk: F) where F: FnOnce() + 'static {
 
 fn foo(x: &()) {
     bar(|| {
-        //~^ ERROR cannot infer
-        //~| ERROR does not fulfill
+        //~^ ERROR does not fulfill
         let _ = x;
     })
 }

src/test/compile-fail/issue-21410.rs

@@ -11,5 +11,5 @@
 fn g<F>(_: F) where F: FnOnce(Option<F>) {}
 
 fn main() {
-    g(|_| {  });
+    g(|_| {  }); //~ ERROR mismatched types
 }

src/test/compile-fail/issue-25439.rs

@@ -15,5 +15,5 @@ fn fix<F>(f: F) -> i32 where F: Fn(Helper<F>, i32) -> i32 {
 }
 
 fn main() {
-    fix(|_, x| x);
+    fix(|_, x| x); //~ ERROR mismatched types
 }

src/test/ui/block-result/issue-3563.stderr

@@ -6,16 +6,5 @@ error[E0599]: no method named `b` found for type `&Self` in the current scope
    |
    = help: did you mean `a`?
 
-error[E0308]: mismatched types
-  --> $DIR/issue-3563.rs:13:9
-   |
-12 |     fn a(&self) {
-   |                 - possibly return type missing here?
-13 |         || self.b()
-   |         ^^^^^^^^^^^ expected (), found closure
-   |
-   = note: expected type `()`
-              found type `[closure@$DIR/issue-3563.rs:13:9: 13:20 self:_]`
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error