Ensure Macro.to_binary work with unary not

Author: José Valim

lib/elixir/lib/macro.ex

@@ -246,6 +246,10 @@ defmodule Macro do
   end
 
   # Unary ops
+  def to_binary({ :not, _, [arg] })  do
+    "not " <> to_binary(arg)
+  end
+
   def to_binary({ op, _, [arg] }) when op in unary_ops do
     atom_to_binary(op, :utf8) <> to_binary(arg)
   end

lib/elixir/test/elixir/macro_test.exs

@@ -245,6 +245,8 @@ defmodule MacroTest do
   end
 
   test :unary_ops_to_binary do
+    assert Macro.to_binary(quote do: not 1) == "not 1"
+    assert Macro.to_binary(quote do: not foo) == "not foo"
     assert Macro.to_binary(quote do: -1) == "-1"
     assert Macro.to_binary(quote do: @foo(bar)) == "@foo(bar)"
   end