Revert "Ensure all runtime_modules loaded before mapping their paths (#12287)"

We don't want to load all modules because some may be
specified as `@compile {:autoload, false}`.

This reverts commit a8aea1c.

Author: josevalim

lib/elixir/lib/kernel/parallel_compiler.ex

@@ -271,8 +271,6 @@ defmodule Kernel.ParallelCompiler do
       for {{:module, module}, _} <- result,
           do: module
 
-    :code.ensure_modules_loaded(runtime_modules)
-
     runtime_modules =
       for module <- runtime_modules,
           path = :code.which(module),