Merge pull request #2357 from D3Hunter/master

#2356 : fix ExceptionInInitializerError on IBM J9

java/core/src/main/java/com/google/protobuf/MapFieldLite.java

@@ -58,7 +58,7 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
   }
 
   @SuppressWarnings({"rawtypes", "unchecked"})
-  private static final MapFieldLite EMPTY_MAP_FIELD = new MapFieldLite(Collections.emptyMap());
+  private static final MapFieldLite EMPTY_MAP_FIELD = new MapFieldLite();
   static {
     EMPTY_MAP_FIELD.makeImmutable();
   }