* java/util/TreeMap.java: New file.
* java/util/TreeSet.java: New file.
* Makefile.am: Add TreeMap and TreeSet. Enable WeakHashMap.
* Makefile.in: Rebuilt.
* java/util/HashSet.java (clone): Use constructor instead of calling
clone on itself.
* java/util/SortedSet.java: Sync with classpath.
* java/util/HashMap.java (hash): Use if statement instead of ternary,
for clarity.
Resolves PR libgcj/1758.
Resolves PR java/1684.
From-SVN: r39657
