Use example TypeError in assert_throws 
diff --git a/encoding/textdecoder-fatal.html b/encoding/textdecoder-fatal.html index 6724115..4cd38e8 100644 --- a/encoding/textdecoder-fatal.html +++ b/encoding/textdecoder-fatal.html 
@@ -56,7 +56,7 @@    bad.forEach(function(t) {  test(function() { - assert_throws({name: 'TypeError'}, function() { + assert_throws(new TypeError(), function() {  new TextDecoder(t.encoding, {fatal: true}).decode(new Uint8Array(t.input))  });  }, 'Fatal flag: ' + t.encoding + ' - ' + t.name);