Expand _AssertionError._evaluateAssertion in the frontend
Expand _AssertionError._evaluateAssertion in the frontend

The call in _evaluationAssertion becomes megamorphic and this is
showing up on Flutter's profile. Avoid the call becoming megamorphic
by inlining the body at the AST level.

BUG=
R=hausner@google.com

Review-Url: https://codereview.chromium.org/2655803007 .

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