patch 7.4.1440
Problem:    Can't build on Windows.
Solution:   Change #ifdefs.  Only define isnan when used.
diff --git a/src/eval.c b/src/eval.c
index c3b7bcc..4afcecc 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -10,6 +10,7 @@
 /*
  * eval.c: Expression evaluation.
  */
+#define USING_FLOAT_STUFF
 
 #include "vim.h"
 
diff --git a/src/json.c b/src/json.c
index 3687645..518a75a 100644
--- a/src/json.c
+++ b/src/json.c
@@ -12,6 +12,7 @@
  *
  * Follows this standard: https://tools.ietf.org/html/rfc7159.html
  */
+#define USING_FLOAT_STUFF
 
 #include "vim.h"
 
diff --git a/src/macros.h b/src/macros.h
index 464eb66..b86c479 100644
--- a/src/macros.h
+++ b/src/macros.h
@@ -327,25 +327,29 @@
    /* for isnan() and isinf() */
 #  include <math.h>
 # endif
-# if defined(WIN32) && !defined(isnan)
-#  define isnan(x) _isnan(x)
-#  define isinf(x) (!_finite(x) && !_isnan(x))
-# else
-#  ifndef HAVE_ISNAN
-    static inline int isnan(double x) { return x != x; }
-#  endif
-#  ifndef HAVE_ISINF
-    static inline int isinf(double x) { return !isnan(x) && isnan(x - x); }
-#  endif
-# endif
-# if !defined(INFINITY)
-#  if defined(DBL_MAX)
-#   define INFINITY (DBL_MAX+DBL_MAX)
+# ifdef USING_FLOAT_STUFF
+#  if defined(WIN32)
+#   ifndef isnan
+#    define isnan(x) _isnan(x)
+#    define isinf(x) (!_finite(x) && !_isnan(x))
+#   endif
 #  else
-#   define INFINITY (1.0 / 0.0)
+#   ifndef HAVE_ISNAN
+     static inline int isnan(double x) { return x != x; }
+#   endif
+#   ifndef HAVE_ISINF
+     static inline int isinf(double x) { return !isnan(x) && isnan(x - x); }
+#   endif
 #  endif
-# endif
-# if !defined(NAN)
-#  define NAN (INFINITY-INFINITY)
+#  if !defined(INFINITY)
+#   if defined(DBL_MAX)
+#    define INFINITY (DBL_MAX+DBL_MAX)
+#   else
+#    define INFINITY (1.0 / 0.0)
+#   endif
+#  endif
+#  if !defined(NAN)
+#   define NAN (INFINITY-INFINITY)
+#  endif
 # endif
 #endif
diff --git a/src/version.c b/src/version.c
index 28e16be..08ce414 100644
--- a/src/version.c
+++ b/src/version.c
@@ -744,6 +744,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1440,
+/**/
     1439,
 /**/
     1438,