remove unneeded destruct

Author: Randl

library/core/src/result.rs

@@ -819,10 +819,8 @@ impl<T, E> Result<T, E> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_unstable(feature = "const_trait_impl", issue = "67792")]
+    #[rustc_allow_const_fn_unstable(const_precise_live_drops)]
     pub const fn map<U, F: ~const FnOnce(T) -> U + ~const Destruct>(self, op: F) -> Result<U, E>
-    where
-        T: ~const Destruct,
-        E: ~const Destruct,
     {
         match self {
             Ok(t) => Ok(op(t)),