Remove some unnessary overrides in java.util

Change-Id: I7033486140dd9c538d8b15a095072c650de757c1

user/super/com/google/gwt/emul/java/util/Collection.java

diff --git a/user/super/com/google/gwt/emul/java/util/Collection.java b/user/super/com/google/gwt/emul/java/util/Collection.java
index c93f686..583efd5 100644
--- a/user/super/com/google/gwt/emul/java/util/Collection.java
+++ b/user/super/com/google/gwt/emul/java/util/Collection.java
@@ -44,19 +44,9 @@
 
   boolean containsAll(Collection<?> c);
 
-  @Override
-  boolean equals(Object o);
-
-  @Override
-  int hashCode();
-
   boolean isEmpty();
 
   @JsIgnore
-  @Override
-  Iterator<E> iterator();
-
-  @JsIgnore
   default Stream<E> parallelStream() {
     // no parallelism in gwt
     return stream();

user/super/com/google/gwt/emul/java/util/Map.java

diff --git a/user/super/com/google/gwt/emul/java/util/Map.java b/user/super/com/google/gwt/emul/java/util/Map.java
index 75bb871..86f0f94 100644
--- a/user/super/com/google/gwt/emul/java/util/Map.java
+++ b/user/super/com/google/gwt/emul/java/util/Map.java
@@ -124,9 +124,6 @@
   @JsIgnore
   Set<Entry<K, V>> entrySet();
 
-  @Override
-  boolean equals(Object o);
-
   @JsIgnore
   default void forEach(BiConsumer<? super K, ? super V> consumer) {
     checkNotNull(consumer);
@@ -142,9 +139,6 @@
     return (currentValue == null && !containsKey(key)) ? defaultValue : currentValue;
   }
 
-  @Override
-  int hashCode();
-
   boolean isEmpty();
 
   Set<K> keySet();