internal: switch some tests to minicore

crates/hir_ty/src/tests/traits.rs

@@ -1492,7 +1492,7 @@ fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
 fn impl_trait_assoc_binding_projection_bug() {
     check_types(
         r#"
-//- /main.rs crate:main deps:std
+//- minicore: iterator
 pub trait Language {
     type Kind;
 }
@@ -1512,20 +1512,6 @@ fn api_walkthrough() {
         node.clone();
     }            //^ {unknown}
 }
-
-//- /std.rs crate:std
-#[prelude_import] use iter::*;
-mod iter {
-    trait IntoIterator {
-        type Item;
-    }
-    trait Iterator {
-        type Item;
-    }
-    impl<T: Iterator> IntoIterator for T {
-        type Item = <T as Iterator>::Item;
-    }
-}
 "#,
     );
 }

crates/test_utils/src/minicore.rs

@@ -227,6 +227,13 @@ pub trait IntoIterator {
                 #[lang = "into_iter"]
                 fn into_iter(self) -> Self::IntoIter;
             }
+            impl<I: Iterator> IntoIterator for I {
+                type Item = I::Item;
+                type IntoIter = I;
+                fn into_iter(self) -> I {
+                    self
+                }
+            }
         }
         pub use self::collect::IntoIterator;
         pub use self::iterator::Iterator;