Fix T37987: MSVC 2013 has C99 headers and warns for out define hypot _hypot for good reason it seems

source/blender/blenlib/BLI_math_base.h

@@ -143,20 +143,27 @@ static const int NAN_INT = 0x7FC00000;
 #define copysignf(a, b) ((float)copysign(a, b))
 #endif
 
-#endif  /* C99 or POSIX.1-2001 */
+#else /* C99 or POSIX.1-2001 */
 
 #ifdef WIN32
 #  ifndef FREE_WINDOWS
 #    ifndef isnan
 #		define isnan(n) _isnan(n)
 #	 endif
-#    define finite _finite
 #    ifndef hypot
 #		define hypot(a, b) _hypot(a, b)
 #	endif
 #  endif
 #endif
 
+#endif  /* C99 or POSIX.1-2001 */
+
+#ifdef WIN32
+#  ifndef FREE_WINDOWS
+#    define finite _finite
+#  endif
+#endif
+
 /* Causes warning:
  * incompatible types when assigning to type 'Foo' from type 'Bar'
  * ... the compiler optimizes away the temp var */