Do not autogenerate docs for defdelegate

This would cause code with multiple clauses where the last
one is a delegate to contain the wrong documentation.

Author: José Valim

lib/elixir/lib/kernel.ex

@@ -4795,10 +4795,6 @@ defmodule Kernel do
       for fun <- List.wrap(funs) do
         {name, args, as, as_args} = Kernel.Utils.defdelegate(fun, opts)
 
-        unless Module.get_attribute(__MODULE__, :doc) do
-          @doc "See `#{inspect(target)}.#{as}/#{:erlang.length(args)}`."
-        end
-
         def unquote(name)(unquote_splicing(args)) do
           unquote(target).unquote(as)(unquote_splicing(as_args))
         end

lib/iex/test/iex/helpers_test.exs

@@ -495,34 +495,6 @@ defmodule IEx.HelpersTest do
       cleanup_modules([Impl, MyBehaviour])
     end
 
-    test "prints documentation for delegates" do
-      filename = "delegate.ex"
-
-      content = """
-      defmodule Delegator do
-        defdelegate func1, to: Delegated
-        @doc "Delegator func2 doc"
-        defdelegate func2, to: Delegated
-      end
-      defmodule Delegated do
-        def func1, do: 1
-        def func2, do: 2
-      end
-      """
-
-      with_file(filename, content, fn ->
-        assert c(filename, ".") |> Enum.sort() == [Delegated, Delegator]
-
-        assert capture_io(fn -> h(Delegator.func1()) end) ==
-                 "* def func1()\n\nSee `Delegated.func1/0`.\n"
-
-        assert capture_io(fn -> h(Delegator.func2()) end) ==
-                 "* def func2()\n\nDelegator func2 doc\n"
-      end)
-    after
-      cleanup_modules([Delegated, Delegator])
-    end
-
     test "prints modules compiled without docs" do
       Code.compiler_options(docs: false)