VOL-1868 move simulated onu from voltha-go to voltha-simonu-adapter

Sourced from voltha-go commit 251a11c0ffe60512318a644cd6ce0dc4e12f4018

Change-Id: Iab179bc2f3dd772ed7f488d1c03d1a84ba75e874
diff --git a/vendor/golang.org/x/sys/unix/timestruct.go b/vendor/golang.org/x/sys/unix/timestruct.go
new file mode 100644
index 0000000..4a672f5
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/timestruct.go
@@ -0,0 +1,82 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package unix
+
+import "time"
+
+// TimespecToNsec converts a Timespec value into a number of
+// nanoseconds since the Unix epoch.
+func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
+
+// NsecToTimespec takes a number of nanoseconds since the Unix epoch
+// and returns the corresponding Timespec value.
+func NsecToTimespec(nsec int64) Timespec {
+	sec := nsec / 1e9
+	nsec = nsec % 1e9
+	if nsec < 0 {
+		nsec += 1e9
+		sec--
+	}
+	return setTimespec(sec, nsec)
+}
+
+// TimeToTimespec converts t into a Timespec.
+// On some 32-bit systems the range of valid Timespec values are smaller
+// than that of time.Time values.  So if t is out of the valid range of
+// Timespec, it returns a zero Timespec and ERANGE.
+func TimeToTimespec(t time.Time) (Timespec, error) {
+	sec := t.Unix()
+	nsec := int64(t.Nanosecond())
+	ts := setTimespec(sec, nsec)
+
+	// Currently all targets have either int32 or int64 for Timespec.Sec.
+	// If there were a new target with floating point type for it, we have
+	// to consider the rounding error.
+	if int64(ts.Sec) != sec {
+		return Timespec{}, ERANGE
+	}
+	return ts, nil
+}
+
+// TimevalToNsec converts a Timeval value into a number of nanoseconds
+// since the Unix epoch.
+func TimevalToNsec(tv Timeval) int64 { return int64(tv.Sec)*1e9 + int64(tv.Usec)*1e3 }
+
+// NsecToTimeval takes a number of nanoseconds since the Unix epoch
+// and returns the corresponding Timeval value.
+func NsecToTimeval(nsec int64) Timeval {
+	nsec += 999 // round up to microsecond
+	usec := nsec % 1e9 / 1e3
+	sec := nsec / 1e9
+	if usec < 0 {
+		usec += 1e6
+		sec--
+	}
+	return setTimeval(sec, usec)
+}
+
+// Unix returns ts as the number of seconds and nanoseconds elapsed since the
+// Unix epoch.
+func (ts *Timespec) Unix() (sec int64, nsec int64) {
+	return int64(ts.Sec), int64(ts.Nsec)
+}
+
+// Unix returns tv as the number of seconds and nanoseconds elapsed since the
+// Unix epoch.
+func (tv *Timeval) Unix() (sec int64, nsec int64) {
+	return int64(tv.Sec), int64(tv.Usec) * 1000
+}
+
+// Nano returns ts as the number of nanoseconds elapsed since the Unix epoch.
+func (ts *Timespec) Nano() int64 {
+	return int64(ts.Sec)*1e9 + int64(ts.Nsec)
+}
+
+// Nano returns tv as the number of nanoseconds elapsed since the Unix epoch.
+func (tv *Timeval) Nano() int64 {
+	return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
+}