Windows: silence compiler warnings

Author: CarterLi

src/util/wcwidth.c

@@ -199,8 +199,13 @@ int mk_wcwidth(wchar_t ucs)
       (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
       (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
       (ucs >= 0xffe0 && ucs <= 0xffe6) ||
+
+#ifndef _WIN32 // sizeof(wchar_t) == 2
       (ucs >= 0x20000 && ucs <= 0x2fffd) ||
-      (ucs >= 0x30000 && ucs <= 0x3fffd)));
+      (ucs >= 0x30000 && ucs <= 0x3fffd) ||
+#endif
+      0
+    ));
 }