Non-SFI mode: Build nacl_helper_nonsfi_unittests

This CL starts to build nacl_helper_nonsfi_unittests.
The binary is not yet enabled to run on bots. It will be done in a following CL.

TEST=Ran locally. Ran build bots. Ran build bots with editing configuration to include nacl_helper_nonsfi_unittests.
BUG=358465

Review URL: https://codereview.chromium.org/1137553003

Cr-Original-Commit-Position: refs/heads/master@{#330069}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 72c418b09bbf90505f54df2b76285650acd97960

all.gyp

@@ -489,6 +489,11 @@
             '../components/nacl.gyp:nacl_loader_unittests',
           ],
         }],
+        ['disable_nacl==0 and disable_nacl_untrusted==0 and OS=="linux"', {
+          'dependencies': [
+            '../components/nacl_nonsfi.gyp:nacl_helper_nonsfi_unittests',
+          ],
+        }],
         ['disable_nacl==0 and disable_nacl_untrusted==0', {
           'dependencies': [
             '../mojo/mojo_nacl_untrusted.gyp:libmojo',