natString.cc (intern): If string's data does not point to this String, make a fresh String that does.

* java/lang/natString.cc (intern):  If string's data does not point to
	this String, make a fresh String that does.

	* java/lang/natString.cc (unintern):  Replace by static function.
	* java/lang/String.java (unintern):  Remove method.

From-SVN: r40990

libjava/java/lang/String.java

@@ -347,6 +347,5 @@ public final class String implements Serializable, Comparable
   private native void init (byte[] chars, int hibyte, int offset, int count);
   private native void init (byte[] chars, int offset, int count, String enc)
     throws UnsupportedEncodingException;
-  private static native void unintern (Object obj);
   private static native void rehash ();
 }