Needed for mingw Firefox build.

Needed by windows.ui.composition.interop.idl.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54819

Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>

Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>

Since wine-gecko now implements synchronous events for image loads in legacy
modes, this is no longer needed.
Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>

Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>

Since we only use in-process plugins anyway.
Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>

Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>

It should set the error code if given a non-zero reserved value.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54799

Also set up the buffer so dumping it is safe enough if the string is
not null-terminated.
And fix the failure messages since the tested value is the string length
in characters, not the buffer size in bytes.