Introduce an "idl"-like format description for analyzer summaries.
Introduce an "idl"-like format description for analyzer summaries.

Not yet used.  This is mostly copied from experiments done earlier in
the year, and is therefore incomplete; I plan to refine this in the
process of fleshing out the implementation and tests.

R=scheglov@google.com

Review URL: https://codereview.chromium.org/1410383004 .

dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk