Auto merge of #39380 - est31:remove_dead_peq, r=jseyfried

Remove dead recursive partial eq impl

Its nowhere used (if it had been used used, the rust stack would have overflown
due to the recursion). Its presence was confusing for mrustc.

cc @thepowersgang

src/librustc_data_structures/accumulate_vec.rs

@@ -25,7 +25,7 @@
 
 use array_vec::{self, Array, ArrayVec};
 
-#[derive(PartialEq, Eq, Hash, Debug)]
+#[derive(Hash, Debug)]
 pub enum AccumulateVec<A: Array> {
     Array(ArrayVec<A>),
     Heap(Vec<A::Element>)

src/librustc_data_structures/array_vec.rs

@@ -52,14 +52,6 @@ fn hash<H>(&self, state: &mut H) where H: Hasher {
     }
 }
 
-impl<A: Array> PartialEq for ArrayVec<A> {
-    fn eq(&self, other: &Self) -> bool {
-        self == other
-    }
-}
-
-impl<A: Array> Eq for ArrayVec<A> {}
-
 impl<A> Clone for ArrayVec<A>
     where A: Array,
           A::Element: Clone {