Use memcmp to improve ForEachStore's performance (#1307)

* Use `memcmp` to improve `ForEachStore`'s performance

* Update Sources/ComposableArchitecture/SwiftUI/ForEachStore.swift

Co-authored-by: Stephen Celis <[email protected]>
(cherry picked from commit 9a01fb412b4cd0bbc4d1032550b5621939430ddb)

# Conflicts:
#	Sources/ComposableArchitecture/SwiftUI/ForEachStore.swift

Author: tgrapperon

Sources/ComposableArchitecture/SwiftUI/ForEachStore.swift

@@ -95,7 +95,10 @@
     {
       self.data = store.state
       self.content = {
-        WithViewStore(store.scope(state: { $0.ids })) { viewStore in
+        WithViewStore(
+          store.scope(state: { $0.ids }),
+          removeDuplicates: areOrderedSetsDuplicates
+        ) { viewStore in
           ForEach(viewStore.state, id: \.self) { id -> EachContent in
             // NB: We cache elements here to avoid a potential crash where SwiftUI may re-evaluate
             //     views for elements no longer in the collection.
@@ -120,4 +123,13 @@
       self.content()
     }
   }
+
+  private func areOrderedSetsDuplicates<ID: Hashable>(lhs: OrderedSet<ID>, rhs: OrderedSet<ID>) -> Bool {
+    var lhs = lhs
+    var rhs = rhs
+    if memcmp(&lhs, &rhs, MemoryLayout<OrderedSet<ID>>.size) == 0 {
+      return true
+    }
+    return lhs == rhs
+  }
 #endif