... and fix output buffer allocation on the way.
I am not aware of any app which strictly depends on the ApplyControlToken / connection shutdown to be implemented. Yet I saw a few games calling ApplyToken to perform the connection shutdown (similar to what is described in [1]). I once implemented that while debugging something and probably it makes some sense support secure connection shutdown once the app tries to do so (which as I understand is now recommended to do before closing socket).
1. https://learn.microsoft.com/en-us/windows/win32/secauthn/shutting-down-an-sc...
-- v2: secur32: Implement ApplyControlToken for SCHANNEL_SHUTDOWN. secur32: Add semi-stub for ApplyControlToken (schannel). secur32: Allocate buffer for either ISC_REQ_ALLOCATE_MEMORY or NULL output in schan_InitializeSecurityContextW(). secure32/tests: Add tests for ApplyControlToken (schannel).