Needed for mingw Firefox build.

.NET Framework passes multiline backtraces to ReportEvent(), which get cut off when passed to debugstr_w().

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54783

We do not use it in this case.

quartz/vmr9: Do not clear the previous allocator and presenter in IVMRFilterConfig9::SetRenderingMode().

There cannot be any previous allocator and presenter. They can only be set by
this function, which cannot be called more than once, or by
IVMRSurfaceAllocatorNotify9::AdviseSurfaceAllocator(), which can only be called
after setting the rendering mode.

Signed-off-by: Eric Pouech <eric.pouech@gmail.com>

Note: it's anyway wrong to search source files inside modules' path
(a proper fix will require revisiting source file handling).
This fix will actually be sufficient when running wine from within
its build tree.
Signed-off-by: Eric Pouech <eric.pouech@gmail.com>