And adjust the return type of CtfImmHideToolbarWnd.
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As with !7572, the Guild Wars 2 installer wants this (but only sometimes, which is why it wasn't included in that MR).
Testing shows that CtfImmRestoreToolbarWnd consumes one pointer-sized argument and (in my surely broken test calls) returns 0.
Examining the app, it calls CtfImmRestoreToolbarWnd with the return value of CtfImmHideToolbarWnd. That implies to me that the return of CtfImmHideToolbarWnd might be more interesting than a BOOL. I adjusted its return to a DWORD, both for that reason and because a BOOL implies that we know more about this function than we do. Let me know if you'd like me to split that into its own commit, or skip the change entirely.