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.

The first test would succeed whether the API touched the buffer or not,
while the second one only succeeds if the API sets the first character
to 0. So keeping the second test is sufficient.