Allow a space after -o in dart2js option parsing.

Allow a space after -o in dart2js option parsing.

Is too much of a hack? We've talked about using the 'args' package
for options parsing, but for now I really just want to make it
easier to run dart2js without surprises.

R=ahe@google.com
BUG=http://dartbug.com/3379

Committed: https://code.google.com/p/dart/source/detail?r=23398

[ahe, 2013-05-30 07:37:55]

I'll review the code when I'm at my desk. From what I could gleam on my phone, I
have a few comments:

I wonder if we could make this slightly more general by passing in an iterator
to the option handlers.

As for the args package, there are still a few things that are holding us back
from using it. Bob tried to fix that, but it broke pub, and then it fell through
the cracks.

[kasperl, 2013-05-30 08:10:18]

PTAL. I decided to generalize the handling a little bit.

[kasperl, 2013-05-30 09:58:07]

PTAL. Now I'm passing an iterator to the option handler (optionally).

[ahe, 2013-05-30 10:02:49]

https://codereview.chromium.org/15891015/diff/6001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/dart2js.dart (right):

https://codereview.chromium.org/15891015/diff/6001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/dart2js.dart:212: new
OptionHandler('-[chv?]+', handleShortOptions),
I would expect a type error here in checked mode.

[kasperl, 2013-05-30 10:45:42]

PTAL. Thanks for spotting my stupid mistakes :-)

[ahe, 2013-05-30 11:28:33]

LGTM!

[kasperl, 2013-05-30 12:11:54]

Committed patchset #4 manually as r23398 (presubmit successful).