windows: add GenerateConsoleCtrlEvent function

ref:
https://docs.microsoft.com/en-us/windows/console/generateconsolectrlevent

Change-Id: Id5db1d4c7d73a142405061353f578b1be93dbbb9
Reviewed-on: https://go-review.googlesource.com/c/sys/+/179538
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

windows/syscall_windows.go

@@ -261,6 +261,7 @@ func NewCallbackCDecl(fn interface{}) uintptr {
 //sys	SetPriorityClass(process Handle, priorityClass uint32) (err error) = kernel32.SetPriorityClass
 //sys	GetPriorityClass(process Handle) (ret uint32, err error) = kernel32.GetPriorityClass
 //sys	SetInformationJobObject(job Handle, JobObjectInformationClass uint32, JobObjectInformation uintptr, JobObjectInformationLength uint32) (ret int, err error)
+//sys	GenerateConsoleCtrlEvent(ctrlEvent uint32, processGroupID uint32) (err error)
 
 // Volume Management Functions
 //sys	DefineDosDevice(flags uint32, deviceName *uint16, targetPath *uint16) (err error) = DefineDosDeviceW

windows/zsyscall_windows.go

@@ -199,6 +199,7 @@ var (
 	procSetPriorityClass                   = modkernel32.NewProc("SetPriorityClass")
 	procGetPriorityClass                   = modkernel32.NewProc("GetPriorityClass")
 	procSetInformationJobObject            = modkernel32.NewProc("SetInformationJobObject")
+	procGenerateConsoleCtrlEvent           = modkernel32.NewProc("GenerateConsoleCtrlEvent")
 	procDefineDosDeviceW                   = modkernel32.NewProc("DefineDosDeviceW")
 	procDeleteVolumeMountPointW            = modkernel32.NewProc("DeleteVolumeMountPointW")
 	procFindFirstVolumeW                   = modkernel32.NewProc("FindFirstVolumeW")
@@ -2146,6 +2147,18 @@ func SetInformationJobObject(job Handle, JobObjectInformationClass uint32, JobOb
 	return
 }
 
+func GenerateConsoleCtrlEvent(ctrlEvent uint32, processGroupID uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGenerateConsoleCtrlEvent.Addr(), 2, uintptr(ctrlEvent), uintptr(processGroupID), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
 func DefineDosDevice(flags uint32, deviceName *uint16, targetPath *uint16) (err error) {
 	r1, _, e1 := syscall.Syscall(procDefineDosDeviceW.Addr(), 3, uintptr(flags), uintptr(unsafe.Pointer(deviceName)), uintptr(unsafe.Pointer(targetPath)))
 	if r1 == 0 {