rpcrt4/tests: NdrVaryingArrayUnmarshall() is broken on Windows

[Ge van Geldorp]

> From: Paul Vriens [mailto:paul.vriens.wine at gmail.com] 
> 
> It looks like we've had exceptions on anything but XP and 
> W2K3 for a long time. 
> The exceptions (as reported on test.winehq.org) for XP and 
> W2K3 started happening after the move to use winetest.exe 
> from test.winehq.org.

I'm not sure which compilers are used. When I use VS2008, the test crashes
consistently on Windows, since in debug mode local vars are initialized with
a 0xcccccccc pattern. MinGW 3.4.5 either initializes the var to zero, or
there happens to be a zero at the right location on the stack when the test
is executed. With MinGW cross-compiled binaries the test doesn't crash for
me on Windows.

Ge.