Ignore exported vars warning

Closes #2798

Signed-off-by: José Valim <[email protected]>

Author: José Valim

lib/elixir/src/elixir_errors.erl

@@ -136,10 +136,13 @@ handle_file_warning(_, File, {Line,erl_lint,{undefined_behaviour,Module}}) ->
 handle_file_warning(_, _File, {Line,erl_lint,{unused_var,_Var}}) when Line =< 0 ->
   ok;
 
-%% Ignore shadowed vars as we guarantee no conflicts ourselves
+%% Ignore shadowed and exported vars as we guarantee no conflicts ourselves
 handle_file_warning(_, _File, {_Line,erl_lint,{shadowed_var,_Var,_Where}}) ->
   ok;
 
+handle_file_warning(_, _File, {_Line,erl_lint,{exported_var,_Var,_Where}}) ->
+  ok;
+
 %% Rewrite nomatch_guard to be more generic it can happen inside if, unless, etc
 handle_file_warning(_, File, {Line, sys_core_fold, nomatch_guard}) ->
   warn(Line, File, "this check/guard will always yield the same result");