Remove From<!> for T *reservation* impl

library/core/src/convert/mod.rs

@@ -793,21 +793,6 @@ const impl<T> From<T> for T {
     }
 }
 
-/// **Stability note:** This impl does not yet exist, but we are
-/// "reserving space" to add it in the future. See
-/// [rust-lang/rust#64715][#64715] for details.
-///
-/// [#64715]: https://github.com/rust-lang/rust/issues/64715
-#[stable(feature = "convert_infallible", since = "1.34.0")]
-#[rustc_reservation_impl = "permitting this impl would forbid us from adding \
-                            `impl<T> From<!> for T` later; see rust-lang/rust#64715 for details"]
-#[rustc_const_unstable(feature = "const_convert", issue = "143773")]
-const impl<T> From<!> for T {
-    fn from(t: !) -> T {
-        t
-    }
-}
-
 // TryFrom implies TryInto
 #[stable(feature = "try_from", since = "1.34.0")]
 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]

tests/ui/never_type/never-from-impl-is-reserved.rs → tests/ui/never_type/never-from-impl-is-not-reserved.rs

@@ -1,5 +1,7 @@
-// check that the `for<T> T: From<!>` impl is reserved
+// check that the `for<T> T: From<!>` impl is not reserved anymore
 
+//@ check-pass
+//
 //@ revisions: current next
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver=coherence
@@ -10,7 +12,6 @@ pub struct MyFoo;
 pub trait MyTrait {}
 
 impl MyTrait for MyFoo {}
-// This will conflict with the first impl if we impl `for<T> T: From<!>`.
-impl<T> MyTrait for T where T: From<!> {} //~ ERROR conflicting implementation
+impl<T> MyTrait for T where T: From<!> {}
 
 fn main() {}