LUCENE-4324: nuke default ctors on some all-static-method util classes

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1377923 13f79535-47bb-0310-9956-ffa450edef68

lucene/core/src/java/org/apache/lucene/index/IndexFileNames.java

@@ -40,6 +40,9 @@ import org.apache.lucene.codecs.Codec;
  */
 
 public final class IndexFileNames {
+  
+  /** No instance */
+  private IndexFileNames() {}
 
   /** Name of the index segment file */
   public static final String SEGMENTS = "segments";

lucene/core/src/java/org/apache/lucene/index/TwoPhaseCommitTool.java

@@ -27,6 +27,9 @@ import java.util.Map;
  * @lucene.experimental
  */
 public final class TwoPhaseCommitTool {
+  
+  /** No instance */
+  private TwoPhaseCommitTool() {}
 
   /**
    * A wrapper of a {@link TwoPhaseCommit}, which delegates all calls to the

lucene/core/src/java/org/apache/lucene/util/SmallFloat.java

@@ -21,6 +21,9 @@ package org.apache.lucene.util;
  * @lucene.internal
  */
 public class SmallFloat {
+  
+  /** No instance */
+  private SmallFloat() {}
 
   /** Converts a 32 bit float to an 8 bit float.
    * <br>Values less than zero are all mapped to zero.