Avoid re-processing invariant expressions.
Avoid re-processing invariant expressions.

There's not currently any risk of running the invariant transform over the
./dist directory more than once during our build process, but it doesn't
hurt to make sure the transform is idempotent.

apollographql/apollo-client,apollostack/apollo-client,apollostack/apollo-client,apollographql/apollo-client,apollostack/apollo-client