Upgrade to Lucene 6.5.0. (elastic/elasticsearch#4950)

This is a sibling of elastic/elasticsearchelastic/elasticsearch#23087.

Original commit: elastic/x-pack-elasticsearch@ab99fbc874

elasticsearch/src/main/java/org/elasticsearch/xpack/security/authz/accesscontrol/FieldSubsetReader.java

@@ -479,6 +479,15 @@ public final class FieldSubsetReader extends FilterLeafReader {
             }
         }
 
+        @Override
+        public long estimatePointCount(String fieldName, IntersectVisitor visitor) {
+            if (hasField(fieldName)) {
+                return in.estimatePointCount(fieldName, visitor);
+            } else {
+                return 0L; // behave as field does not exist
+            }
+        }
+
         @Override
         public byte[] getMinPackedValue(String fieldName) throws IOException {
             if (hasField(fieldName)) {