ICU 56 update step 1

source/i18n/fmtableimp.h

 /*
 *******************************************************************************
-* Copyright (C) 2010-2012, International Business Machines Corporation and    *
+* Copyright (C) 2010-2014, International Business Machines Corporation and    *
 * others. All Rights Reserved.                                                *
 *******************************************************************************
 */
 
 #ifndef FMTABLEIMP_H
 #define FMTABLEIMP_H
 
+#include "digitlst.h"
+
+U_NAMESPACE_BEGIN
 
 /**
  * @internal
  */
 struct FmtStackData {
   DigitList stackDecimalNum;   // 128
   //CharString stackDecimalStr;  // 64
   //                         -----
   //                         192 total
 };
 
+/** 
+ * Maximum int64_t value that can be stored in a double without chancing losing precision.
+ *   IEEE doubles have 53 bits of mantissa, 10 bits exponent, 1 bit sign.
+ *   IBM Mainframes have 56 bits of mantissa, 7 bits of base 16 exponent, 1 bit sign.
+ * Define this constant to the smallest value from those for supported platforms.
+ * @internal
+ */
+static const int64_t MAX_INT64_IN_DOUBLE = 0x001FFFFFFFFFFFFFLL;
 
+U_NAMESPACE_END
 
 #endif