Add back UTF-32 for now and fix a MSVC build issue

source/common/ucnv_u32.c

 /*  
 **********************************************************************
 *   Copyright (C) 2002-2015, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 **********************************************************************
 *   file name:  ucnv_u32.c
 *   encoding:   US-ASCII
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 2002jul01
 *   created by: Markus W. Scherer
 *
 *   UTF-32 converter implementation. Used to be in ucnv_utf.c.
 */
 
 #include "unicode/utypes.h"
 
-#if !UCONFIG_NO_CONVERSION && !UCONFIG_ONLY_HTML_CONVERSION
+#if !UCONFIG_NO_CONVERSION
 
 #include "unicode/ucnv.h"
 #include "unicode/utf.h"
 #include "ucnv_bld.h"
 #include "ucnv_cnv.h"
 #include "cmemory.h"
 
 #define MAXIMUM_UCS2            0x0000FFFF
 #define MAXIMUM_UTF             0x0010FFFF
 #define HALF_SHIFT              10
@@ skipping 1201 matching lines @@
     FALSE, FALSE,
     0,
     0,
     { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } /* reserved */
 };
 
 const UConverterSharedData _UTF32Data = 
         UCNV_IMMUTABLE_SHARED_DATA_INITIALIZER(&_UTF32StaticData, &_UTF32Impl);
 
 #endif