Build nacl_helper_nonsfi with GN

build/config/nacl/BUILD.gn

Index: build/config/nacl/BUILD.gn
diff --git a/build/config/nacl/BUILD.gn b/build/config/nacl/BUILD.gn
index 541bb0c475d19e9ec40802a108dc2f0cf5209c3b..6d3244cb5993568039d65a484fcd6e58b57b41db 100644
--- a/build/config/nacl/BUILD.gn
+++ b/build/config/nacl/BUILD.gn
@@ -38,6 +38,8 @@ source_set("nacl_base") {
 config("compiler") {
   configs = []
   cflags = []
+  ldflags = []
+  libs = []
 
   if (is_clang && current_cpu != "pnacl") {
     # -no-integrated-as is the default in nacl-clang for historical
@@ -48,6 +50,29 @@ config("compiler") {
     # everywhere for consistency (and possibly quicker builds).
     cflags += [ "-integrated-as" ]
   }
+  if (is_nacl_nonsfi) {
+    cflags += [ "--pnacl-allow-translate" ]
+    ldflags += [
+      "--pnacl-allow-translate",
+      "--pnacl-allow-native",
+      "-Wl,--noirt",
+      "-Wt,--noirt",
+      "-Wt,--noirtshim",
+
+      # The clang driver automatically injects -lpthread when using libc++, but
+      # the toolchain doesn't have it yet.  To get around this, use
+      # -nodefaultlibs and make each executable target depend on
+      # "//native_client/src/nonsfi/irt:nacl_sys_private".
+      "-nodefaultlibs",
+    ]
+    libs += [
+      "c++",
+      "m",
+      "c",
+      "pnaclmm",
+    ]
+    include_dirs = [ "//native_client/src/public/linux_syscalls" ]
+  }
 
   asmflags = cflags
 }