Don't define COBJMACROS in objbase.h.
Update the Wine sources accordingly.

diff --git a/dlls/mlang/mlang.c b/dlls/mlang/mlang.c
index 54d7c86..6deb6cc 100644
--- a/dlls/mlang/mlang.c
+++ b/dlls/mlang/mlang.c
@@ -25,6 +25,8 @@
 #include <stdarg.h>
 #include <stdio.h>
 
+#define COBJMACROS
+
 #include "windef.h"
 #include "winbase.h"
 #include "wingdi.h"