Add missing casts.  The GCC folks applied a similar patch in
GCC's own copy of Classpath:
http://gcc.gnu.org/ml/java/2007-05/msg00039.html .

--- classpath-0.98/javax/management/NotificationBroadcasterSupport.java	2009-07-30 16:52:08.000000000 +0200
+++ classpath-0.98/javax/management/NotificationBroadcasterSupport.java	2009-07-30 16:51:58.000000000 +0200
@@ -218,7 +218,7 @@
   {
     if (info == null || info.length == 0)
       return new MBeanNotificationInfo[0];
-    return info.clone();
+    return (MBeanNotificationInfo[]) info.clone();
   }
 
   /**

--- classpath-0.98/java/util/concurrent/CopyOnWriteArrayList.java	2008-03-27 18:39:25.000000000 +0100
+++ classpath-0.98/java/util/concurrent/CopyOnWriteArrayList.java	2009-07-30 17:08:30.000000000 +0200
@@ -147,7 +148,7 @@ public class CopyOnWriteArrayList<E> 
    */
   public CopyOnWriteArrayList(E[] array)
   {
-    data = array.clone();
+    data = (E[]) array.clone();
   }
 
   /**
@@ -364,7 +365,7 @@ public class CopyOnWriteArrayList<E> 
   public synchronized E set(int index, E e)
   {
     E result = data[index];
-    E[] newData = data.clone();
+    E[] newData = (E[]) data.clone();
     newData[index] = e;
     data = newData;
     return result;

--- classpath-0.98/java/util/EnumMap.java	2007-07-24 17:26:36.000000000 +0200
+++ classpath-0.98/java/util/EnumMap.java	2009-07-30 17:12:19.000000000 +0200
@@ -398,7 +398,7 @@ public class EnumMap<K extends Enum<K>, 
 	// Can't happen.
 	result = null;
       }
-    result.store = store.clone();
+    result.store = (V[]) store.clone();
     return result;
   }
 
--- classpath-0.98/gnu/java/lang/reflect/GenericSignatureParser.java	2008-03-01 11:13:31.000000000 +0100
+++ classpath-0.98/gnu/java/lang/reflect/GenericSignatureParser.java	2009-07-30 17:14:24.000000000 +0200
@@ -75,7 +75,7 @@ final class TypeVariableImpl extends Typ
     public Type[] getBounds()
     {
         resolve(bounds);
-        return bounds.clone();
+        return (Type[]) bounds.clone();
     }
 
     public GenericDeclaration getGenericDeclaration()
@@ -154,7 +154,7 @@ final class ParameterizedTypeImpl extend
 
     public Type[] getActualTypeArguments()
     {
-        return typeArgs.clone();
+        return (Type[]) typeArgs.clone();
     }
 
     public Type getRawType()

--- classpath-0.98/external/jsr166/java/util/ArrayDeque.java	2006-12-10 21:25:40.000000000 +0100
+++ classpath-0.98/external/jsr166/java/util/ArrayDeque.java	2009-07-30 17:15:35.000000000 +0200
@@ -787,7 +790,7 @@ public class ArrayDeque<E> extends Abstr
             ArrayDeque<E> result = (ArrayDeque<E>) super.clone();
             // Classpath local: we don't have Arrays.copyOf yet.
             // result.elements = Arrays.copyOf(elements, elements.length);
-            result.elements = elements.clone();
+            result.elements = (E[]) elements.clone();
             return result;
 
         } catch (CloneNotSupportedException e) {