Enable nacl on 32-bit x86 linux GN builds.

build/toolchain/nacl/BUILD.gn

 # 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.
 
 import("//build/config/sysroot.gni")
 import("//build/toolchain/nacl_toolchain.gni")
 
 nacl_toolchain_dir = rebase_path("//native_client/toolchain", root_build_dir)
 os_toolchain_dir = "${nacl_toolchain_dir}/${current_os}_x86"
 
@@ skipping 135 matching lines @@
   toolchain_revision = pnacl_newlib_rev
   toolchain_cpu = "x86"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/i686-nacl-"
   is_clang = true
 
   cc = toolprefix + "clang"
   cxx = toolprefix + "clang++"
   ar = toolprefix + "ar"
   readelf = toolprefix + "readelf"
 
+  tls_edit_label =
+      "//native_client/src/tools/tls_edit:tls_edit($host_toolchain)"
+  host_toolchain_out_dir =
+      rebase_path(get_label_info(tls_edit_label, "root_out_dir"),
+                  root_build_dir)
+
   # Some IRT implementations (notably, Chromium's) contain C++ code,
   # so we need to link w/ the C++ linker.
-  ld = "${python_path} ${link_irt} --tls-edit=tls_edit --link-cmd=${cxx} --readelf-cmd=${readelf}"
+  ld = "${python_path} ${link_irt} --tls-edit=${host_toolchain_out_dir}/tls_edit --link-cmd=${cxx} --readelf-cmd=${readelf}"
 
   # TODO(ncbray): depend on link script
   deps = [
-    "//native_client/src/tools/tls_edit:tls_edit($host_toolchain)",
+    tls_edit_label,
   ]
 }
 
 nacl_toolchain("irt_x64") {
   toolchain_package = "pnacl_newlib"
   toolchain_revision = pnacl_newlib_rev
   toolchain_cpu = "x64"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/x86_64-nacl-"
   is_clang = true
 
@@ skipping 27 matching lines @@
 
   # Some IRT implementations (notably, Chromium's) contain C++ code,
   # so we need to link w/ the C++ linker.
   ld = "${python_path} ${link_irt} --tls-edit=tls_edit --link-cmd=${cxx} --readelf-cmd=${readelf}"
 
   # TODO(ncbray): depend on link script
   deps = [
     "//native_client/src/tools/tls_edit:tls_edit($host_toolchain)",
   ]
 }