native client + hermetic toolchain + gn

src/trusted/service_runtime/BUILD.gn

Index: src/trusted/service_runtime/BUILD.gn
diff --git a/src/trusted/service_runtime/BUILD.gn b/src/trusted/service_runtime/BUILD.gn
index 268ca8940de3b5f7645b43f2a831b2328912ae1c..4eb9f9d7170e8b64adcbd87b82b8cc0f58089f2a 100644
--- a/src/trusted/service_runtime/BUILD.gn
+++ b/src/trusted/service_runtime/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/toolchain/toolchain.gni")
 import("//native_client/src/trusted/asm.gni")
 
 source_set("sel_main") {
@@ -326,6 +327,7 @@ if (current_os == "mac") {
     ]
     args = rebase_path(sources, root_build_dir) +
            rebase_path(outputs, root_build_dir)
+    args += [ hermetic_xcode_path]
   }
 }