parse.y: disable past scope warnings

* parse.y (gettable_gen): disable warnings of possible reference
  to a local variable defined in a past scope.
  [ruby-core:67162] [Bug #10661]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49082 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_parse.rb

@@ -874,7 +874,9 @@ x = __ENCODING__
     assert_warning(/#{a}/) {eval("#{a} = 1; /(?<#{a}>)/ =~ ''")}
   end
 
+=begin
   def test_past_scope_variable
     assert_warning(/past scope/) {catch {|tag| eval("BEGIN{throw tag}; tap {a = 1}; a")}}
   end
+=end
 end