Do not rely on atoms phash2 to check for function determinism
Do not rely on atoms phash2 to check for function determinism

This fixes the build on Erlang/OTP master.

pedrosnk/elixir,pedrosnk/elixir,kelvinst/elixir,kimshrier/elixir,lexmag/elixir,elixir-lang/elixir,michalmuskala/elixir,ggcampinho/elixir,ggcampinho/elixir,kelvinst/elixir,joshprice/elixir,kimshrier/elixir,lexmag/elixir