Add sharedfrontend package

Add sharedfrontend package

- initial element model includes Element, LibraryElement and ClassElement
- AccessSemantics moved to sharedfrontend to be utilized from both analyzer2dart and dart2js.

BUG=
R=brianwilkerson@google.com, paulberry@google.com

Committed: https://code.google.com/p/dart/source/detail?r=43635

Reverted: https://code.google.com/p/dart/source/detail?r=43637

[Johnni Winther, 2015-02-05 16:02:47]

johnniwinther@google.com changed reviewers:
+ brianwilkerson@google.com, paulberry@google.com

[Brian Wilkerson, 2015-02-05 17:09:37]

In order to add this package we need to add a dependency on 'sharedfrontend' to
the analyzer's pubspec. Which means that we'll also need to publish
'sharedfrontend' on pub.dartlang.org.

Other than that, LGTM.

https://codereview.chromium.org/898113002/diff/1/pkg/sharedfrontend/lib/eleme...
File pkg/sharedfrontend/lib/elements.dart (right):

https://codereview.chromium.org/898113002/diff/1/pkg/sharedfrontend/lib/eleme...
pkg/sharedfrontend/lib/elements.dart:10: /// in the element * model. Generally
speaking, the element model is a semantic
nit: Remove the '*'

[Paul Berry, 2015-02-05 17:30:44]

lgtm

[Johnni Winther, 2015-02-10 10:11:33]

New patchsets have been uploaded after l-g-t-m from
brianwilkerson@google.com,paulberry@google.com

[Johnni Winther, 2015-02-10 10:13:03]

Updated the pubspec.yaml to contain a path reference. I guess publishing
sharedfrontend can be postponed to the next publishing of analyzer.

https://codereview.chromium.org/898113002/diff/1/pkg/sharedfrontend/lib/eleme...
File pkg/sharedfrontend/lib/elements.dart (right):

https://codereview.chromium.org/898113002/diff/1/pkg/sharedfrontend/lib/eleme...
pkg/sharedfrontend/lib/elements.dart:10: /// in the element * model. Generally
speaking, the element model is a semantic
On 2015/02/05 17:09:37, Brian Wilkerson wrote:
> nit: Remove the '*'

Done.

[Johnni Winther, 2015-02-10 10:46:48]

Committed patchset #2 (id:20001) manually as 43635 (presubmit successful).

[Johnni Winther, 2015-02-10 15:12:47]

PTAL at the last patch.

[Brian Wilkerson, 2015-02-10 15:52:58]

I still don't like the architecture that we're heading toward. I'd like to
discuss this CL in our meeting tomorrow. In particular, I'd like to understand
why dart2js can't just depend on analyzer directly instead of relying on an
intermediate package.

https://codereview.chromium.org/898113002/diff/40001/pkg/analyzer/pubspec.yaml
File pkg/analyzer/pubspec.yaml (right):

https://codereview.chromium.org/898113002/diff/40001/pkg/analyzer/pubspec.yam...
pkg/analyzer/pubspec.yaml:13: path: ../../pkg/sharedfrontend/
Unless I'm misunderstanding something, we can publish this to pub.dartlang.org
(which means we wouldn't be able to publish a new version of analyzer if we
needed to). This only works when downloading the analyzer package as part of the
SVN repository, which many users don't do.