Update test -- here we get a RFC 1214 warning (that will eventually be

an error) but the bugfix causes this warning to propagate and become an
unresolved variable instead of a `TyError`, so we wind up seeing an
obscure inference error afterwards, which is somewhat unfortunate,
and suggests this bugfix can cause RFC 1214 warnings to become
errors.

Author: nikomatsakis

src/test/run-pass/issue-25810.rs

@@ -14,7 +14,9 @@ fn main() {
     println!("{:?}",y);
 }
 
-trait Foo {
+trait Foo
+    where for<'a> &'a Self: Bar
+{
     fn foo<'a>(&'a self) -> <&'a Self as Bar>::Output;
 }