Make javaemul.internal.ArrayStamper public.

ArrayStamper will be used by elemental2.

Change-Id: Ib26dfbc22c77d956290990ffe9d3f87bffc4b51d

user/super/com/google/gwt/emul/javaemul/internal/ArrayStamper.java

diff --git a/user/super/com/google/gwt/emul/javaemul/internal/ArrayStamper.java b/user/super/com/google/gwt/emul/javaemul/internal/ArrayStamper.java
index 7da1402..a92686b 100644
--- a/user/super/com/google/gwt/emul/javaemul/internal/ArrayStamper.java
+++ b/user/super/com/google/gwt/emul/javaemul/internal/ArrayStamper.java
@@ -18,7 +18,7 @@
 /**
  * A utility to provide array stamping. Provided as a separate class to simplify super-source.
  */
-class ArrayStamper {
+public class ArrayStamper {
   public static native <T> T[] stampJavaTypeInfo(Object array, T[] referenceType) /*-{
     return @com.google.gwt.lang.Array::stampJavaTypeInfo(
         Ljava/lang/Object;[Ljava/lang/Object;)(array, referenceType);