Auto merge of #86041 - bstrie:unmagic-array-copy, r=jackh726

Replace Copy/Clone compiler magic on arrays with library impls

With const generics the compiler no longer needs to fake these impls.

src/test/ui/builtin-clone-unwind.rs

@@ -53,7 +53,7 @@ fn main() {
         ].clone();
     });
 
-    assert!(result.is_err());
+    assert!(child.is_err());
     assert_eq!(
         1,
         Rc::strong_count(&counter)

src/test/ui/chalkify/builtin-copy-clone.rs

@@ -23,11 +23,12 @@ fn test_copy_clone<T: Copy + Clone>(arg: T) {
 fn foo() { }
 
 fn main() {
+    // FIXME: add closures when they're considered WF
     test_copy_clone(foo);
     let f: fn() = foo;
     test_copy_clone(f);
-    // FIXME: add closures when they're considered WF
-    test_copy_clone([1; 56]);
+    // FIXME(#86252): reinstate array test after chalk upgrade
+    //test_copy_clone([1; 56]);
     test_copy_clone((1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1));
     test_copy_clone((1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, true, 'a', 1.1));
     test_copy_clone(());

src/test/ui/error-codes/E0206.rs

@@ -1,9 +1,3 @@
-type Foo = [u8; 256];
-
-impl Copy for Foo { }
-//~^ ERROR the trait `Copy` may not be implemented for this type
-//~| ERROR only traits defined in the current crate can be implemented for arbitrary types
-
 #[derive(Copy, Clone)]
 struct Bar;
 

src/test/ui/error-codes/E0206.stderr

@@ -1,27 +1,9 @@
 error[E0206]: the trait `Copy` may not be implemented for this type
-  --> $DIR/E0206.rs:3:15
-   |
-LL | impl Copy for Foo { }
-   |               ^^^ type is not a structure or enumeration
-
-error[E0206]: the trait `Copy` may not be implemented for this type
-  --> $DIR/E0206.rs:10:15
+  --> $DIR/E0206.rs:4:15
    |
 LL | impl Copy for &'static mut Bar { }
    |               ^^^^^^^^^^^^^^^^ type is not a structure or enumeration
 
-error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
-  --> $DIR/E0206.rs:3:1
-   |
-LL | impl Copy for Foo { }
-   | ^^^^^^^^^^^^^^---
-   | |             |
-   | |             this is not defined in the current crate because arrays are always foreign
-   | impl doesn't use only types from inside the current crate
-   |
-   = note: define and implement a trait or new type instead
+error: aborting due to previous error
 
-error: aborting due to 3 previous errors
-
-Some errors have detailed explanations: E0117, E0206.
-For more information about an error, try `rustc --explain E0117`.
+For more information about this error, try `rustc --explain E0206`.