ntdll: Added a DLL_WINE_PREATTACH call to DllMain for builtins.

By returning FALSE from this call, a builtin dll can specify that we
should try to load the native one instead.

include/winnt.h

diff --git a/include/winnt.h b/include/winnt.h
index 199383b..053f014 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -469,7 +469,9 @@
 #define	DLL_PROCESS_ATTACH	1	/* attach process (load library) */
 #define	DLL_THREAD_ATTACH	2	/* attach new thread */
 #define	DLL_THREAD_DETACH	3	/* detach thread */
-
+#ifdef __WINESRC__
+#define DLL_WINE_PREATTACH      8       /* called before process attach for Wine builtins */
+#endif
 
 /* u.x.wProcessorArchitecture (NT) */
 #define PROCESSOR_ARCHITECTURE_INTEL	0