Added 32-bit version of nonsfi monacl shell

mojo/nacl/BUILD.gn

Index: mojo/nacl/BUILD.gn
diff --git a/mojo/nacl/BUILD.gn b/mojo/nacl/BUILD.gn
index 44e3b3e3d6ef7393b06f205882d49cbd8bce2ecd..e6a4146bfe0b3f69a8f86c1c5ad10b64a45a2769 100644
--- a/mojo/nacl/BUILD.gn
+++ b/mojo/nacl/BUILD.gn
@@ -33,6 +33,13 @@ if (!is_nacl) {
   }
 }
 
+group("monacl_shell_nonsfi_x86") {

[Mark Seaborn, 2015/09/08 23:57:43]

Should this be added as a dependency of group("mojo_nacl"), so that it's
included in the set of targets built by the bots?  Currently the bots don't
build it.

Also, I think this should be conditionalised on "x86-32 or x86-64", otherwise
we'd attempt to build it when targeting ARM.

[Sean Klein, 2015/09/09 17:37:07]

I think it should be a dependency of "mojo_nacl_tests", as it is a testonly
executable (and the regular monacl_shell is there too).

Also, adding the conditional to the deps -- this way, the target still exists
and can be referenced on ARM without throwing an error, it just doesn't build
anything.

+  testonly = true
+  deps = [
+    ":monacl_shell_nonsfi(//build/toolchain/linux:clang_x86)",

[Mark Seaborn, 2015/09/08 23:57:43]

Since this is Linux-specific, it seems like the target should be conditionalised
on Linux too.  Though I'm not sure whether the codebase as a whole is intended
to support non-Linux OSes.

Is there a way to do this without assuming Clang?  i.e. Is there a way to ask
for "the 32-bit variant of whatever toolchain we're using (whether it's GCC or
Clang or something else)"?  If not, can you add a comment to explain the
assumption and say it's not ideal?

[Sean Klein, 2015/09/09 17:37:07]

Added a conditional on "is_linux".

Comment added.

+  ]
+}
+
 # Untrusted code
 if (is_nacl) {
   # Unit test for the Mojo public API.