test: add test for default icon resource

wfassoc-cdylib/cbindgen/wfassoc.h

@@ -36,15 +36,6 @@ using CStyleString = const char*;
  * And we expose this type as an opaque handle for visiting your created object.
  */
 using Token = uint64_t;
-#else  // __cplusplus
-typedef const char *CStyleString;
-typedef uint64_t Token;
-#endif  // __cplusplus
-
-
-// Special treat for ICON because it may be defined by Windows header.
-#ifndef _WINDEF_
-#ifdef __cplusplus
 /** 
  * @brief Type representing an icon handle (opaque pointer)
  * 
@@ -52,9 +43,10 @@ typedef uint64_t Token;
  */
 using HICON = void*;
 #else  // __cplusplus
+typedef const char *CStyleString;
+typedef uint64_t Token;
 typedef void *HICON;
 #endif  // __cplusplus
-#endif
 
 
 #ifdef __cplusplus