unix: add support for timerfd syscalls on Linux

timerfd_create, timerfd_gettime and timerfd_settime syscalls have been added.
Fixes golang/go#38733

Change-Id: I306d68103b6efb2515c74f384646210c4b68f66e
Reviewed-on: https://go-review.googlesource.com/c/sys/+/230798
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
diff --git a/unix/zsyscall_linux.go b/unix/zsyscall_linux.go
index fd2dae8..df21782 100644
--- a/unix/zsyscall_linux.go
+++ b/unix/zsyscall_linux.go
@@ -1450,6 +1450,37 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func TimerfdCreate(clockid int, flags int) (fd int, err error) {
+	r0, _, e1 := RawSyscall(SYS_TIMERFD_CREATE, uintptr(clockid), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func TimerfdGettime(fd int, currValue *ItimerSpec) (err error) {
+	_, _, e1 := RawSyscall(SYS_TIMERFD_GETTIME, uintptr(fd), uintptr(unsafe.Pointer(currValue)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func TimerfdSettime(fd int, flags int, newValue *ItimerSpec, oldValue *ItimerSpec) (err error) {
+	_, _, e1 := RawSyscall6(SYS_TIMERFD_SETTIME, uintptr(fd), uintptr(flags), uintptr(unsafe.Pointer(newValue)), uintptr(unsafe.Pointer(oldValue)), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Tgkill(tgid int, tid int, sig syscall.Signal) (err error) {
 	_, _, e1 := RawSyscall(SYS_TGKILL, uintptr(tgid), uintptr(tid), uintptr(sig))
 	if e1 != 0 {