Arrays methods

[Brian Goetz]

>   - add Arrays.fill() methods

We have an unfortunate collection.  We already have:

      void fill(Object[] a, Object val) {

If we added

      <T> void fill(T[], IntFunction<T> gen)

then existing calls to

   fill(array, null)

would become ambiguous.  Doh.  (But the other 17 forms are not 
problematic.)

Any suggestions for alternate names?