Include cmath so we get std::isnan

xfa/src/fxbarcode/utils.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 _BC_UTILS_H_
 #define _BC_UTILS_H_
 typedef CFX_MapPtrTemplate<void*, int32_t> CFX_PtrToInt32;
 FX_BOOL BC_FX_ByteString_Replace(CFX_ByteString& dst,
@@ skipping 45 matching lines @@
 };
 #if (_FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN64_)
 #include <limits>
 #elif(_FX_OS_ == _FX_MACOSX_ || _FX_OS_ == _FX_LINUX_DESKTOP_ || \
       _FX_OS_ == _FX_IOS_)
 #include <limits.h>
 #endif
 #if (_FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN64_)
 #define FXSYS_isnan(x) _isnan(x)
 #elif(_FX_OS_ == _FX_MACOSX_ || _FX_OS_ == _FX_IOS_)
-#include <math.h>
+#include <cmath>
 #define FXSYS_isnan(x) std::isnan(x)
 #elif(_FX_OS_ == _FX_LINUX_DESKTOP_ || _FX_OS_ == _FX_ANDROID_)
 #include <math.h>
 #define FXSYS_isnan(x) isnan(x)
 #endif
 #if (_FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN64_)
 #define FXSYS_nan() (std::numeric_limits<float>::quiet_NaN())
 #elif(_FX_OS_ == _FX_MACOSX_ || _FX_OS_ == _FX_LINUX_DESKTOP_ || \
       _FX_OS_ == _FX_IOS_ || _FX_OS_ == _FX_ANDROID_)
 #define FXSYS_nan() NAN
@@ skipping 130 matching lines @@
 #define THREE_DIGIT_DATA_LENGTH_SIZE 23
 #define THREE_DIGIT_PLUS_DIGIT_DATA_LENGTH_SIZE 57
 #define FOUR_DIGIT_DATA_LENGTH_SIZE 17
 #define BC_EXCEPTION_CHECK_ReturnVoid(e) \
   if (e != BCExceptionNO)                \
     return;
 #define BC_EXCEPTION_CHECK_ReturnValue(e, v) \
   if (e != BCExceptionNO)                    \
     return v;
 #endif