Add top level build script for building packages.

build_tools/naclports.sh

Index: build_tools/naclports.sh
diff --git a/build_tools/naclports.sh b/build_tools/naclports.sh
new file mode 100755
index 0000000000000000000000000000000000000000..cf0d7c027eaef01449e9e28077840ac253399d3a
--- /dev/null
+++ b/build_tools/naclports.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+# Copyright (c) 2014 The Native Client Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# Executable entry point for building nacl ports.
+# This script must be run from the indivdual port directory (containing
+# pkg_info and build.sh).  Most of the code and heavy lifting is in
+# common.sh.
+
+readonly SCRIPT_DIR=$(cd "$(dirname "$BASH_SOURCE")" ; pwd)
+
+if [ ! -f pkg_info ]; then
+  echo "No pkg_info found in current directory"
+  exit 1
+fi
+source pkg_info
+
+source ${SCRIPT_DIR}/common.sh
+
+if [ -f build.sh ]; then
+  source build.sh
+fi
+
+NaclportsMain "$@"