Update newly failing UI tests

tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.rs

@@ -1,12 +1,10 @@
-// check-pass
 // normalize-stderr-test: "`.*`" -> "`DEF_ID`"
 // normalize-stdout-test: "`.*`" -> "`DEF_ID`"
 // edition:2018
 
 pub async fn f() -> impl std::fmt::Debug {
-    // rustdoc doesn't care that this is infinitely sized
     #[derive(Debug)]
-    enum E {
+    enum E { //~ ERROR
         This(E),
         Unit,
     }

tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.stderr

@@ -0,0 +1,16 @@
+error[E0072]: recursive type `DEF_ID` has infinite size
+  --> $DIR/infinite-recursive-type-impl-trait-return.rs:7:5
+   |
+LL |     enum E {
+   |     ^^^^^^
+LL |         This(E),
+   |              - recursive without indirection
+   |
+help: insert some indirection (e.g., a `DEF_ID`) to break the cycle
+   |
+LL |         This(Box<E>),
+   |              ++++ +
+
+error: aborting due to previous error
+
+For more information about this error, try `DEF_ID`.

tests/rustdoc-ui/infinite-recursive-type-impl-trait.rs

@@ -1,8 +1,5 @@
-// check-pass
-
 fn f() -> impl Sized {
-    // rustdoc doesn't care that this is infinitely sized
-    enum E {
+    enum E { //~ ERROR
         V(E),
     }
     unimplemented!()

tests/rustdoc-ui/infinite-recursive-type-impl-trait.stderr

@@ -0,0 +1,16 @@
+error[E0072]: recursive type `f::E` has infinite size
+  --> $DIR/infinite-recursive-type-impl-trait.rs:2:5
+   |
+LL |     enum E {
+   |     ^^^^^^
+LL |         V(E),
+   |           - recursive without indirection
+   |
+help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to break the cycle
+   |
+LL |         V(Box<E>),
+   |           ++++ +
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0072`.