Starting work on full GN build

build/toolchain/fnl/BUILD.gn

-# 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.
-
-import("//build/toolchain/gcc_toolchain.gni")
-
-declare_args() {
-  toolchain_prefix = ""
-}
-
-gcc_toolchain("target") {
-  assert(toolchain_prefix != "", "Must provide toolchain_prefix")
-
-  cc = "${toolchain_prefix}gcc"
-  cxx = "${toolchain_prefix}g++"
-  ar = "${toolchain_prefix}ar"
-  ld = cxx
-  readelf = "${toolchain_prefix}readelf"
-  nm = "${toolchain_prefix}nm"
-
-  toolchain_cpu = "${target_cpu}"
-  toolchain_os = "linux"
-  is_clang = is_clang
-}