[libxml2] Remove isinf/isnan emulation in win32config.h

[Nick Wellnhofer <nwellnhof src gnome org>]

commit ae3cf4831ca6295bd9c638c199fb40b50d35bd4a
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu Mar 3 23:57:59 2022 +0100

    Remove isinf/isnan emulation in win32config.h
    
    There's already a better fallback in xpath.c.

 include/win32config.h | 57 ---------------------------------------------------
 1 file changed, 57 deletions(-)
---
diff --git a/include/win32config.h b/include/win32config.h
index d804404a..41618cc1 100644
--- a/include/win32config.h
+++ b/include/win32config.h
@@ -21,63 +21,6 @@
  */
 #undef except
 
-#define HAVE_ISINF
-#define HAVE_ISNAN
-#include <math.h>
-#if defined(_MSC_VER) || defined(__BORLANDC__)
-/* MS C-runtime has functions which can be used in order to determine if
-   a given floating-point variable contains NaN, (+-)INF. These are 
-   preferred, because floating-point technology is considered proprietary
-   by MS and we can assume that their functions know more about their 
-   oddities than we do. */
-#include <float.h>
-/* Bjorn Reese figured a quite nice construct for isinf() using the _fpclass
-   function. */
-#ifndef isinf
-#define isinf(d) ((_fpclass(d) == _FPCLASS_PINF) ? 1 \
-       : ((_fpclass(d) == _FPCLASS_NINF) ? -1 : 0))
-#endif
-/* _isnan(x) returns nonzero if (x == NaN) and zero otherwise. */
-#ifndef isnan
-#define isnan(d) (_isnan(d))
-#endif
-#else /* _MSC_VER */
-#ifndef isinf
-static int isinf (double d) {
-    int expon = 0;
-    double val = frexp (d, &expon);
-    if (expon == 1025) {
-        if (val == 0.5) {
-            return 1;
-        } else if (val == -0.5) {
-            return -1;
-        } else {
-            return 0;
-        }
-    } else {
-        return 0;
-    }
-}
-#endif
-#ifndef isnan
-static int isnan (double d) {
-    int expon = 0;
-    double val = frexp (d, &expon);
-    if (expon == 1025) {
-        if (val == 0.5) {
-            return 0;
-        } else if (val == -0.5) {
-            return 0;
-        } else {
-            return 1;
-        }
-    } else {
-        return 0;
-    }
-}
-#endif
-#endif /* _MSC_VER */
-
 #if defined(_MSC_VER)
 #define mkdir(p,m) _mkdir(p)
 #if _MSC_VER < 1900