make sure modules from erts are returned

lib/elixir_sense/core/applications.ex

@@ -26,8 +26,10 @@ defmodule ElixirSense.Core.Applications do
   @spec get_modules_from_applications() :: [module]
   # TODO use :code.all_available |> Enum.map(fn {m, _, _} -> :"#{m}" end) on otp 23+
   # as it returns more
-  # NOTE this function does not return modules from :erts app as it is not loaded
   def get_modules_from_applications do
+    # :erts app is not loaded by default
+    Application.load(:erts)
+
     for [app] <- loaded_applications(),
         {:ok, modules} = :application.get_key(app, :modules),
         module <- modules do

test/elixir_sense/all_modules_test.exs

@@ -10,5 +10,6 @@ defmodule ElixirSense.Providers.ModulesTest do
     assert "ElixirSense.Providers" not in modules
     assert "ElixirSense.Providers.Definition" in modules
     assert ":kernel" in modules
+    assert ":erlang" in modules
   end
 end

test/elixir_sense/core/erlang_html_test.exs

@@ -16,6 +16,7 @@ defmodule ElixirSense.Core.ErlangHtmlTest do
           :eldap,
           :erl_docgen,
           :erl_interface,
+          :erts,
           :et,
           :eunit,
           :ftp,