make_event_watcher requires the event handle have EVENT_MODIFY_STATE

[jonwis]

Consider this:

struct event_and_watcher {
    wil::unique_event eventName;
    wil::unique_event_watcher watcher;
};
event_and_watcher make_event_watcher(wchar_t const* name, void (*pfn)()) {
    event_and_watcher retval;
    if (retval.eventName.try_open(name, SYNCHRONIZE)) {
        retval.watcher = wil::make_event_watcher(retval.eventName.get(), pfn);
    }
    return retval;
}
auto g_w = make_event_watcher(L"AnotherEventName", [] { ReactToEvent(); });

When the event is signaled and the TP wait callback is invoked here:

wil/include/wil/resource.h

Lines 3915 to 3924 in 6f60a1b

	static void CALLBACK wait_callback(PTP_CALLBACK_INSTANCE, void* context, TP_WAIT* pThreadPoolWait, TP_WAIT_RESULT)
	{
	auto pThis = static_cast<details::event_watcher_state*>(context);
	// Manual events must be re-set to avoid missing the last notification.
	pThis->m_event.ResetEvent();
	// Call the client before re-arming to ensure that multiple callbacks don't
	// run concurrently.
	pThis->m_callback();
	SetThreadpoolWait(pThreadPoolWait, pThis->m_event.get(), nullptr); // valid params ensure success
	}

... the ResetEvent fails with a failfast:

wil/include/wil/resource.h

Lines 2502 to 2505 in 6f60a1b

	inline void __stdcall ResetEvent(HANDLE h) WI_NOEXCEPT
	{
	__FAIL_FAST_ASSERT_WIN32_BOOL_FALSE__(::ResetEvent(h));
	}

... because I don't have Reset rights, only Synchronize.

Consider a policy flag to make that Reset optional.