examples: add a very simple package for benchmarking

Change-Id: I23fd2b578a8c2217e96f9e3e2f879f2a43ece93d

_examples/simple/simple.go

@@ -0,0 +1,9 @@
+// Copyright 2015 The go-python Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// simple is a simple package.
+package simple
+
+// Func is a simple func
+func Func() {}