Do not emit type warning on generated nodes

Closes #13727.

Author: josevalim

lib/elixir/lib/module/types/helpers.ex

@@ -91,9 +91,13 @@ defmodule Module.Types.Helpers do
   Emits a warnings.
   """
   def warn(module, warning, meta, stack, context) do
-    {fun, arity} = stack.function
-    location = {stack.file, meta, {stack.module, fun, arity}}
-    %{context | warnings: [{module, warning, location} | context.warnings]}
+    if Keyword.get(meta, :generated, false) do
+      context
+    else
+      {fun, arity} = stack.function
+      location = {stack.file, meta, {stack.module, fun, arity}}
+      %{context | warnings: [{module, warning, location} | context.warnings]}
+    end
   end
 
   @doc """

lib/elixir/test/elixir/module/types/expr_test.exs

@@ -6,6 +6,12 @@ defmodule Module.Types.ExprTest do
   import TypeHelper
   import Module.Types.Descr
 
+  defmacro generated(x) do
+    quote generated: true do
+      unquote(x).foo()
+    end
+  end
+
   test "literal" do
     assert typecheck!(true) == atom([true])
     assert typecheck!(false) == atom([false])
@@ -21,6 +27,10 @@ defmodule Module.Types.ExprTest do
     assert typecheck!(fn -> :ok end) == fun()
   end
 
+  test "generated" do
+    assert typecheck!([x = 1], generated(x)) == dynamic()
+  end
+
   describe "funs" do
     test "incompatible" do
       assert typewarn!([%x{}], x.(1, 2)) ==