Add DebuggerTypeProxy to ListDictionaryInternal

src/libraries/System.Private.CoreLib/src/System/Collections/ListDictionaryInternal.cs

@@ -10,6 +10,7 @@ namespace System.Collections
     /// Recommended for collections that typically include fewer than 10 items.
     /// </summary>
     [DebuggerDisplay("Count = {count}")]
+    [DebuggerTypeProxy(typeof(ListDictionaryInternalDebugView))]
     [Serializable]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
     // Needs to be public to support binary serialization compatibility
@@ -405,5 +406,31 @@ private sealed class DictionaryNode
             public object? value;
             public DictionaryNode? next;
         }
+
+        private sealed class ListDictionaryInternalDebugView
+        {
+            private readonly ListDictionaryInternal _list;
+
+            public ListDictionaryInternalDebugView(ListDictionaryInternal list)
+            {
+                ArgumentNullException.ThrowIfNull(list);
+                _list = list;
+            }
+
+            [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
+            public KeyValuePairs[] Items
+            {
+                get
+                {
+                    var array = new KeyValuePairs[_list.count];
+                    int index = 0;
+                    for (DictionaryNode? node = _list.head; node != null; node = node.next)
+                    {
+                        array[index++] = new KeyValuePairs(node.key, node.value);
+                    }
+                    return array;
+                }
+            }
+        }
     }
 }