Issue #14252: Fix subprocess.Popen.terminate() to not raise an error under Windows when the child process has already exited.
diff --git a/PC/_subprocess.c b/PC/_subprocess.c
index 2338f30..f9a79a7 100644
--- a/PC/_subprocess.c
+++ b/PC/_subprocess.c
@@ -684,6 +684,7 @@
     defint(d, "WAIT_OBJECT_0", WAIT_OBJECT_0);
     defint(d, "CREATE_NEW_CONSOLE", CREATE_NEW_CONSOLE);
     defint(d, "CREATE_NEW_PROCESS_GROUP", CREATE_NEW_PROCESS_GROUP);
+    defint(d, "STILL_ACTIVE", STILL_ACTIVE);
 
     return m;
 }