"mix help <anything> <anything_else>" crashes

[alco]

Oops.

$ mix help compile --list
** (FunctionClauseError) no function clause matching in Mix.Tasks.Help.run/1
    (mix) lib/mix/tasks/help.ex:18: Mix.Tasks.Help.run(["compile", "--list"])
    (mix) lib/mix/cli.ex:63: Mix.CLI.run_task/2
    (elixir) src/elixir_lexical.erl:17: :elixir_lexical.run/2
    (elixir) lib/code.ex:303: Code.require_file/2

$ mix help blah blah blah
** (FunctionClauseError) no function clause matching in Mix.Tasks.Help.run/1
    (mix) lib/mix/tasks/help.ex:18: Mix.Tasks.Help.run(["blah", "blah", "blah"])
    (mix) lib/mix/cli.ex:63: Mix.CLI.run_task/2
    (elixir) src/elixir_lexical.erl:17: :elixir_lexical.run/2
    (elixir) lib/code.ex:303: Code.require_file/2

Version: e39b32f