feat: add ext status for cdylib

wfassoc/src/win32/concept.rs

@@ -575,6 +575,18 @@ impl Drop for IconRc {
     }
 }
 
+// SAFETY:
+// Win32 HICON can be safely moved between different threads naturally.
+unsafe impl Send for IconRc {}
+
+// SAFETY:
+// When multiple threads calling this struct, there is no conflict between them,
+// because this struct only provide HICON itself.
+// 
+// However, the caller should ensure that all calls using this HICON 
+// follow Win32 thread model.
+unsafe impl Sync for IconRc {}
+
 // endregion
 
 // region: String Resource