Handle deserialized compilation of closures

pkg/compiler/lib/src/common/codegen.dart

Index: pkg/compiler/lib/src/common/codegen.dart
diff --git a/pkg/compiler/lib/src/common/codegen.dart b/pkg/compiler/lib/src/common/codegen.dart
index 4640bdb4902275f5ce91b9b9f10b2f97e1c78f1c..9685c42616d3a474a053c7afe55c7a0ead0c051e 100644
--- a/pkg/compiler/lib/src/common/codegen.dart
+++ b/pkg/compiler/lib/src/common/codegen.dart
@@ -235,8 +235,8 @@ class CodegenWorkItem extends WorkItem {
     // generation could spuriously be adding dependencies on things we know we
     // don't need.
     assert(invariant(
-        element, compiler.enqueuer.resolution.hasBeenProcessed(element),
-        message: "$element has not been resolved."));
+        element, compiler.backend.frontend.hasResolvedAst(element),
+        message: "$element has no resolved ast."));
     ResolvedAst resolvedAst = compiler.backend.frontend.getResolvedAst(element);
     return new CodegenWorkItem.internal(resolvedAst, compilationContext);
   }