Access parameter data in Annotations, as well as fixed export visibility

Access parameter data in Annotations, as well as fixed export visibility
calculation.

BUG=
R=alanknight@google.com, johnniwinther@google.com

Committed: https://code.google.com/p/dart/source/detail?r=35768

[Emily Fortuna, 2014-04-30 23:24:42]

This is a fix for the Angular issue:
https://code.google.com/p/dart/issues/detail?id=17982

Peter, you need only look at the stuff in sdk/lib/_internal/ (which was copied
wholesale from your CL https://codereview.chromium.org/257863002/) and
pkg/docgen/lib/src/models/annotation.dart where I use the API.

I'm pretty badly twisting the Visitor (+Observer) Pattern to get the pointer to
the corresponding mirror (since everything in docgen is a "MirrorBased object")
AND the syntax from the AST visitor. I'm happy to take other suggestions of how
to write this better, but this was the best way I could find that didn't require
further modification of the dart2js compiler.

[Alan Knight, 2014-04-30 23:47:13]

LGTM.

[ahe, 2014-05-01 09:01:48]

I'd be more comfortable if Johnni or Florian would review this.

[Emily Fortuna, 2014-05-01 18:20:42]

bump Johnni or Florian?

[Johnni Winther, 2014-05-01 18:45:27]

On 2014/05/01 18:20:42, Emily Fortuna wrote:
> bump Johnni or Florian?

Florian is on vacation this week. I started reviewing today and will finish
tomorrow.

[kevmoo, 2014-05-02 00:21:22]

DBC

Tests? I ran this through my pretty formatted output.

I noticed some changes of annotations: "dart-core.Deprecated" to
"dart-core.deprecation", for example.

But I also so a lot of cases where an exported library took precedence over the
source.

For example: comments in matcher/matcher.Description have 'commentFram' from
'unittest-matcher.Description.length'

unittest exports matcher, so I wouldn't expect the source of a comment to come
from unittest

https://codereview.chromium.org/268583002/diff/20001/sdk/lib/_internal/compil...
File sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirrors.dart
(right):

https://codereview.chromium.org/268583002/diff/20001/sdk/lib/_internal/compil...
sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirrors.dart:462:
final node;
Types?

https://codereview.chromium.org/268583002/diff/20001/sdk/lib/_internal/compil...
sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirrors.dart:467:
Mirror resolvedMirror(node) {
Type of node?

[Johnni Winther, 2014-05-02 05:55:35]

lgtm

[Emily Fortuna, 2014-05-05 21:31:38]

Committed patchset #3 manually as r35768 (presubmit successful).