prohibits too many items from being added to a constant pool.

the previous commit was wrong.

src/main/javassist/bytecode/ConstPool.java

      */
     public void write(DataOutputStream out) throws IOException
     {
-        if (numOfItems < 0 || Short.MAX_VALUE < numOfItems)
+        if (numOfItems < 0 || ((1 << 16) - 1) < numOfItems)
             throw new IOException("too many constant pool items " + numOfItems);
 
         out.writeShort(numOfItems);

src/test/javassist/JvstTest5.java

         CtClass cc = sloader.makeClass("TooManyConstPoolItems");
         ClassFile cf = cc.getClassFile();
         ConstPool cPool = cf.getConstPool();
-        for (int i = 0; i <= 65527; i++)
-            cPool.addIntegerInfo(i);
+        int size = cPool.getSize();
+        while (cPool.getSize() < 65536 - 6)
+            cPool.addIntegerInfo(cPool.getSize());
+
+        cc.writeFile();
+        cc.defrost();
+        cPool.addIntegerInfo(-1);
         try {
             cc.writeFile();
             fail("too many items were accepted");