time: use Duration(C.INT64_MAX) as infinite (#10539)

vlib/time/time_windows.c.v

@@ -225,3 +225,15 @@ pub fn wait(duration Duration) {
 pub fn sleep(duration Duration) {
 	C.Sleep(int(duration / millisecond))
 }
+
+// some Windows system functions (e.g. `C.WaitForSingleObject()`) accept an `u32`
+// value as *timeout in milliseconds* with the special value `u32(-1)` meaning "infinite"
+pub fn (d Duration) sys_milliseconds() u32 {
+	if d >= u32(-1) * millisecond { // treat 4294967295000000 .. C.INT64_MAX as "infinite"
+		return u32(-1)
+	} else if d <= 0 {
+		return 0 // treat negative timeouts as 0 - consistent with Unix behaviour
+	} else {
+		return u32(d / millisecond)
+	}
+}