iseq.c: mark parents of wrapped iseq

* iseq.c (iseqw_mark): as wrapped iseq is isolated from the call
  stack, it needs to take care of its parent and ancestors, so
  that they do not become orphans.  [ruby-core:72620] [Bug #11928]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53514 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_exception.rb

@@ -701,6 +701,12 @@ end.join
     assert_equal(%i[a b c d e f g], e.local_variables.sort)
   end
 
+  def test_name_error_info_parent_iseq_mark
+    assert_separately(['-', File.join(__dir__, 'bug-11928.rb')], <<-'end;')
+      -> {require ARGV[0]}.call
+    end;
+  end
+
   def test_output_string_encoding
     # "\x82\xa0" in cp932 is "\u3042" (Japanese hiragana 'a')
     # change $stderr to force calling rb_io_write() instead of fwrite()