* autoload.cc (winmm): Remove time functions. Don't treat

	* autoload.cc (winmm): Remove time functions.  Don't treat
	unloadable wave functions as fatal.
	* hires.h (hires_ms::timeGetTime_ns): New private method.
	(hires_ms::dmsecs): Call timeGetTime_ns here.
	* ntdll.h (struct _KSYSTEM_TIME): Define.
	(KUSER_SHARED_DATA): Redefine to allow access to InterruptTime.
	(SharedUserData): Define here.
	(NtQueryTimerResolution): Declare.
	(NtSetTimerResolution): Declare.
	* path.cc (SharedUserData): Move to ntdll.h.
	* times.cc (hires_ms::timeGetTime_ns): New private method.
	Use throughout instead of timeGetTime.  Document entire functionality
	of timeGetTime in case we need it.
	(hires_ms::resolution): Try a call to NtQueryTimerResolution
	to fetch current period.  Fall back to heuristic if that fails.
	Cast to DWORD in assignments to minperiod.
	(clock_setres): Align period to possible values per a call to
	NtQueryTimerResolution.  Explain why.  Replace calls to timeBeginPeriod
	and timeEndPeriod with underlying call to NtSetTimerResolution.  Use
	status code from NtSetTimerResolution to compute errno.
	Convert period to ULONGLONG and store 100ns value to simplify code.