Fix issue 3623:	The unmodifiable collections are missing .toString()

Review by: scottb



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5873 8db76d5a-ed1c-0410-87a9-c151d255dfc7

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

diff --git a/user/super/com/google/gwt/emul/java/util/Collections.java b/user/super/com/google/gwt/emul/java/util/Collections.java
index 52d5f98..d5528f2 100644
--- a/user/super/com/google/gwt/emul/java/util/Collections.java
+++ b/user/super/com/google/gwt/emul/java/util/Collections.java
@@ -83,6 +83,10 @@
     public <E> E[] toArray(E[] a) {
       return coll.toArray(a);
     }
+    
+    public String toString() {
+      return coll.toString();
+    }
   }
 
   static class UnmodifiableList<T> extends UnmodifiableCollection<T> implements