Make the fuchsia mojo/public repo the source of truth.

mojo/public/go/system/system_nacl.go

Index: mojo/public/go/system/system_nacl.go
diff --git a/mojo/public/go/system/system_nacl.go b/mojo/public/go/system/system_nacl.go
deleted file mode 100644
index e3ec4a437e7d8e329d87e872a57b71ae7b1fda7d..0000000000000000000000000000000000000000
--- a/mojo/public/go/system/system_nacl.go
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2015 The Chromium 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 include_mojo_cgo
-
-package system
-
-import "runtime/nacl"
-
-// NaCl uses the runtime's Mojo IRT based system implementation.
-func init() {
-	sysImpl = &nacl.MojoNaClSystem{}
-}