[PATCH v2] ntdll: Fix overflow if running 32bit app w/ wine64

[Vincent Povirk]

> > you get the Out of Memory error that is fixed by this patch. Applying
> > this patch allows these applications to work as they currently do
> > under Windows.
>
> For .NET binaries this should be solved by generating a PE64 header to
> replace the PE32 one.

Does the test case work with native .NET? If not, we need to fix that first.

If it does, we should change the header in _CorValidateImage.