[ddc-kernel] Compile return and arrow functions
[ddc-kernel] Compile return and arrow functions

Compile return statements.  Kernel function bodies are statements, not
necessarily blocks.  In that case, blockify the JS function body.

Bug:
Change-Id: Ibbed1c2039b103151b7244774f3daf8992264a88
Reviewed-on: https://dart-review.googlesource.com/15280
Reviewed-by: Vijay Menon <671ecbb18d31a1c038875027dcfe976af959ea9f@google.com>
Commit-Queue: Kevin Millikin <a6737c91ef81c790d8ad0ae8762bd5b2332a6e42@google.com>

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