Build nacl_helper_nonsfi with GN

build/config/nacl/config.gni

Index: build/config/nacl/config.gni
diff --git a/build/config/nacl/config.gni b/build/config/nacl/config.gni
index b743910ef4a8e4a950a92c5595d181b6cbc3a0e8..b757fdce370ea29a0521483e45f06ed3a83afde5 100644
--- a/build/config/nacl/config.gni
+++ b/build/config/nacl/config.gni
@@ -7,6 +7,7 @@ declare_args() {
   # is assumed to be the default one; use this to determine whether Glibc
   # is being used instead.
   is_nacl_glibc = false
+  is_nacl_nonsfi = false

[brettw, 2015/10/26 00:49:47]

This can just be defined outside of the declare args block (i.e. at the end of
this file) as:
  is_nacl_nonsfi = current_toolchain ==
"//build/toolchain/nacl:newlib_pnacl_nonsfi"
Then you can delete the gcc_toolchain plumbing for this flag.

Also, this needs a comment (I would mention what nonsfi actually is and what
it's used for).

[Petr Hosek, 2015/10/26 01:55:11]

Done.

 }
 
 nacl_toolchain_dir = "//native_client/toolchain/${host_os}_x86"