Use intermediate typedef.

include/process.h

@@ -163,9 +163,13 @@ static inline PDB WINE_UNUSED *PROCESS_Current(void)
 
 /* definitions contained in Windows process.h file */
 /* FIXME: all the stuff above should be moved somewhere else */
-ULONG _beginthread(VOID (*)(LPVOID),UINT,LPVOID);
+
+typedef void (*LPBEGINTHREAD)(LPVOID);
+typedef UINT (WINAPI *LPBEGINTHREADEX)(LPVOID);
+
+ULONG _beginthread(LPBEGINTHREAD,UINT,LPVOID);
 void  _endthread(void);
-ULONG _beginthreadex(LPVOID,UINT,UINT (WINAPI*) (LPVOID),LPVOID,UINT,LPUINT);
+ULONG _beginthreadex(LPVOID,UINT,LPBEGINTHREADEX,LPVOID,UINT,LPUINT);
 void  _endthreadex(UINT);
 
 #endif  /* __WINE_PROCESS_H */