patch 7.4.2150
Problem:    Warning with MinGW 64. (John Marriott)
Solution:   Change return type. (Ken Takata)
diff --git a/src/os_win32.c b/src/os_win32.c
index 7122177..54f2e88 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -4212,7 +4212,7 @@
  * process. This way avoid to hang up vim totally if the children
  * process take a long time to process the lines.
  */
-    static DWORD WINAPI
+    static unsigned int __stdcall
 sub_process_writer(LPVOID param)
 {
     HANDLE	    g_hChildStd_IN_Wr = param;