Log Message:
lang/elixir: Update to 1.6.3.

Elixir
- [Code.Formatter] Support comments in the middle of pipelines,
  when and | expressions
- [Code.Formatter] Consider commas when breaking groups
- [Code.Formatter] Ensure proper precedence between & and operators
- [Code.Formatter] Consider .formatter.exs when formatting stdin

Logger
- [Logger.Translator] Ensure logger doesn't crash when reporting
  named DynamicSupervisor