use ES3.1 headers
use ES3.1 headers

We now compile with ES3.1 headers but we make sure we can still compile
with ES3.0 headers (still needed for iOS).
google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament