Update the semantics of the 'special-command' flag given to the test script.

Update the semantics of the 'special-command' flag given to the test script.

This gives the suffix as arguments to the existing executable, not as a suffix to the whole command.
Committed: https://code.google.com/p/dart/source/detail?r=13100

[Mads Ager (google), 2012-10-01 13:55:29]

Please update the comments in connection with the test option as well in
test_options.dart.

See output of ./tools/test.py --help

[ricow1, 2012-10-02 05:32:20]

On 2012/10/01 13:55:29, Mads Ager wrote:
> Please update the comments in connection with the test option as well in
> test_options.dart.
> 
> See output of ./tools/test.py --help
Done

[Mads Ager (google), 2012-10-02 05:33:19]

LGTM