Fix FXSYS_itoa() implementation.

core/include/fxcrt/fx_system.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef CORE_INCLUDE_FXCRT_FX_SYSTEM_H_
 #define CORE_INCLUDE_FXCRT_FX_SYSTEM_H_
 
 #include <assert.h>
@@ skipping 250 matching lines @@
    (((uint8_t*)(p))[2] << 8) | (((uint8_t*)(p))[3]))
 #define FXSYS_HIBYTE(word) ((uint8_t)((word) >> 8))
 #define FXSYS_LOBYTE(word) ((uint8_t)(word))
 #define FXSYS_HIWORD(dword) ((FX_WORD)((dword) >> 16))
 #define FXSYS_LOWORD(dword) ((FX_WORD)(dword))
 int32_t FXSYS_atoi(const FX_CHAR* str);
 int32_t FXSYS_wtoi(const FX_WCHAR* str);
 int64_t FXSYS_atoi64(const FX_CHAR* str);
 int64_t FXSYS_wtoi64(const FX_WCHAR* str);
 const FX_CHAR* FXSYS_i64toa(int64_t value, FX_CHAR* str, int radix);
-const FX_WCHAR* FXSYS_i64tow(int64_t value, FX_WCHAR* str, int radix);
 int FXSYS_round(FX_FLOAT f);
 #define FXSYS_Mul(a, b) ((a) * (b))
 #define FXSYS_Div(a, b) ((a) / (b))
 #define FXSYS_MulDiv(a, b, c) ((a) * (b) / (c))
 #define FXSYS_sqrt2(a, b) (FX_FLOAT) FXSYS_sqrt((a) * (a) + (b) * (b))
 #ifdef __cplusplus
 };
 #endif
 
 // To print a size_t value in a portable way:
@@ skipping 28 matching lines @@
 
 // Prevent a function from ever being inlined, typically because we'd
 // like it to appear in stack traces.
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 #define NEVER_INLINE __declspec(noinline)
 #else  // _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 #define NEVER_INLINE __attribute__((__noinline__))
 #endif  // _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 
 #endif  // CORE_INCLUDE_FXCRT_FX_SYSTEM_H_