Hide also ULONG while including <windows.h>

LibreOffice's deprecated ULONG is sal_uIntPtr, and thus 64 bits on
64-bit Windows, unlike Windows's ULONG which is 32 bits on both 32-
and 64-bit Windows. So we must hide ULONG, too, to avoid compilation
errors on 64-bit Windows.

tools/inc/tools/postwin.h

@@ -47,6 +47,7 @@
 #undef UINT64
 #undef INT32
 #undef UINT32
+#undef ULONG
 #endif
 #undef Folder
 #undef GradientStyle_RECT

tools/inc/tools/prewin.h

@@ -37,6 +37,7 @@
 #define UINT64       WIN_UINT64
 #define INT32        WIN_INT32
 #define UINT32       WIN_UINT32
+#define ULONG        WIN_ULONG
 #endif
 
 #define Rectangle    BLA_Rectangle