-- v2: kernelbase: Implement QueueUserAPC2(). ntdll: Use NtContinueEx in KiUserApcDispatcher on x64. ntdll: Implement QUEUE_USER_APC_CALLBACK_DATA_CONTEXT in NtQueueApcThreadEx2() on x64. ntdll: Pass user APC flags to call_user_apc_dispatcher(). ntdll: Validate reserve handle in NtQueueApcThreadEx2(). ntdll: Add semi-stub for NtQueueApcThreadEx2().