frog: allow optional arguments in implicit method closures.

frog: allow optional arguments in implicit method closures.

This fixes http://dartbug.com/854, but not bug 282. We need either fixing 282 or
this to implement a better API in unittest.dart (which works in the vm and
dart2js).

Committed: https://code.google.com/p/dart/source/detail?r=6850

[sra1, 2012-04-21 03:33:14]

DBC.
lgtm - I nearly made this change several times since it is so easy.

https://chromiumcodereview.appspot.com/10168024/diff/1/frog/gen.dart
File frog/gen.dart (right):

https://chromiumcodereview.appspot.com/10168024/diff/1/frog/gen.dart#newcode979
frog/gen.dart:979: defWriter.writeln('var \$bound =
this.${m.jsname}.bind(this);');
nit.
$bound could be any name (e.g. 'f') since there are no free vars here.
no need for $.

[sra1, 2012-04-21 03:33:56]

Please run presubmit to regenerate minfrog.

[kasperl, 2012-04-23 05:32:44]

LGTM.