Fix Windows build by removing an overly strict assertion.
Fix Windows build by removing an overly strict assertion.

The Windows compiler may align members so that the assertion
about the size of RawCode and the offset data_ does not match anymore.

TBR=iposva@google.com

Review URL: https://codereview.chromium.org//312153004

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@36993 260f80e4-7a28-3924-810f-c04153c831b5

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