Add thunks for MojoGetRights(), etc.

mojo/public/platform/nacl/libmojo.cc

Index: mojo/public/platform/nacl/libmojo.cc
diff --git a/mojo/public/platform/nacl/libmojo.cc b/mojo/public/platform/nacl/libmojo.cc
index 415d95003d083b4919cee2a1da7c6b2618aaa952..716877ce5468f7a4160d4f6d14134eb09510b204 100644
--- a/mojo/public/platform/nacl/libmojo.cc
+++ b/mojo/public/platform/nacl/libmojo.cc
@@ -53,6 +53,13 @@ MojoResult MojoClose(MojoHandle handle) {
   return irt_mojo->MojoClose(handle);
 }
 
+MojoResult MojoGetRights(MojoHandle handle, MojoHandleRights* rights) {
+  struct nacl_irt_mojo* irt_mojo = get_irt_mojo();
+  if (!irt_mojo)
+    abort();
+  return irt_mojo->MojoGetRights(handle, rights);
+}
+
 MojoResult MojoWait(MojoHandle handle,
                     MojoHandleSignals signals,
                     MojoDeadline deadline,