José Valim
5eb2efe543
Previously, the internal Elixir expansion pass worked directly on
Macro.Env. However, this poised an issue, if we want to track
more information in the pass, we ended up exposing it on
Macro.Env, making it larger, and potentially slowing down
operations such as __ENV__ serialization.
This commit refactors the expansion pass to work with two
structures, the Macro.Env struct and a #elixir_ex{} record.