Add cygwin support

Berrysoft · Berrysoft · commit 3f8c474def91 · 2025-03-07T23:41:31.000+08:00
diff --git a/src/unix.rs b/src/unix.rs
@@ -78,6 +78,7 @@ extern "C" {
             target_os = "android",
             target_os = "espidf",
             target_os = "vxworks",
+            target_os = "cygwin",
             target_env = "newlib"
         ),
         link_name = "__errno"
