windows: add GetSystemTimePreciseAsFileTime

https://msdn.microsoft.com/en-us/library/windows/desktop/hh706895(v=vs.85).aspx

Change-Id: I6e6a6642c041fad046ae7db725a27e7e94bfbfba
Reviewed-on: https://go-review.googlesource.com/39610Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

windows/syscall_windows.go

@@ -109,6 +109,7 @@ func NewCallbackCDecl(fn interface{}) uintptr
 //sys	GetComputerNameEx(nametype uint32, buf *uint16, n *uint32) (err error) = GetComputerNameExW
 //sys	SetEndOfFile(handle Handle) (err error)
 //sys	GetSystemTimeAsFileTime(time *Filetime)
+//sys	GetSystemTimePreciseAsFileTime(time *Filetime)
 //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
 //sys	CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (handle Handle, err error)
 //sys	GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) (err error)

windows/zsyscall_windows.go

@@ -93,6 +93,7 @@ var (
 	procGetComputerNameExW                 = modkernel32.NewProc("GetComputerNameExW")
 	procSetEndOfFile                       = modkernel32.NewProc("SetEndOfFile")
 	procGetSystemTimeAsFileTime            = modkernel32.NewProc("GetSystemTimeAsFileTime")
+	procGetSystemTimePreciseAsFileTime     = modkernel32.NewProc("GetSystemTimePreciseAsFileTime")
 	procGetTimeZoneInformation             = modkernel32.NewProc("GetTimeZoneInformation")
 	procCreateIoCompletionPort             = modkernel32.NewProc("CreateIoCompletionPort")
 	procGetQueuedCompletionStatus          = modkernel32.NewProc("GetQueuedCompletionStatus")
@@ -807,6 +808,11 @@ func GetSystemTimeAsFileTime(time *Filetime) {
 	return
 }
 
+func GetSystemTimePreciseAsFileTime(time *Filetime) {
+	syscall.Syscall(procGetSystemTimePreciseAsFileTime.Addr(), 1, uintptr(unsafe.Pointer(time)), 0, 0)
+	return
+}
+
 func GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) {
 	r0, _, e1 := syscall.Syscall(procGetTimeZoneInformation.Addr(), 1, uintptr(unsafe.Pointer(tzi)), 0, 0)
 	rc = uint32(r0)