Parse defined variables in command-line analyzer

Parse defined variables in command-line analyzer. We can't actually make use of them until we translate a new version, but it's one step closer.

R=pquitslund@google.com

Committed: https://code.google.com/p/dart/source/detail?r=36508

[pquitslund, 2014-05-22 16:22:40]

LGTM % type annotation nits.

https://codereview.chromium.org/290733010/diff/1/pkg/analyzer/lib/options.dart
File pkg/analyzer/lib/options.dart (right):

https://codereview.chromium.org/290733010/diff/1/pkg/analyzer/lib/options.dar...
pkg/analyzer/lib/options.dart:153: Map<String, String> definedVariables =
<String, String>{};
I think we want to lose the type annotation for consistency's sake...

https://codereview.chromium.org/290733010/diff/1/pkg/analyzer/lib/options.dar...
pkg/analyzer/lib/options.dart:264: List<String>
parseDefinedVariables(List<String> args, Map<String, String> definedVariables) {
This whole method should probably be cleansed of type annotations.

[Brian Wilkerson, 2014-05-22 16:42:08]

Thanks for the feedback. I agree that we need to be consistent with our use of
type annotations, but I'll revisit this later.

[Brian Wilkerson, 2014-05-22 16:45:25]

Committed patchset #1 manually as r36508 (presubmit successful).