Remove stub-generation test for dartc from test.dart stub-generator.

Remove stub-generation test for dartc from test.dart stub-generator.

All components now just compile the existing generated test files.

BUG=
TEST=tools/test.dart -cmost stub-generator --mode=debug,release

Committed: https://code.google.com/p/dart/source/detail?r=4089

[Bill Hesse, 2012-02-09 16:20:58]

With the test generation removed, the suite reduces to a StandardTestSuite. 
Only dartc and vm components run - frog and leg are disabled in the status
files.  Browser components are also disabled.

[zundel, 2012-02-09 16:31:35]

lgtm