Store ResolvedAst on AstElement

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 8ad503c74cc650b79e8d429e2d8555a8abdc7825..9860b0880ccb9c28b10af958c448068868cb0f78 100644
--- a/pkg/compiler/lib/src/common/codegen.dart
+++ b/pkg/compiler/lib/src/common/codegen.dart
@@ -234,9 +234,9 @@ class CodegenWorkItem extends WorkItem {
     // missing call of form registry.registerXXX. Alternatively, the code
     // generation could spuriously be adding dependencies on things we know we
     // don't need.
-    assert(invariant(element, compiler.backend.frontend.hasResolvedAst(element),
+    assert(invariant(element, element.hasResolvedAst,
         message: "$element has no resolved ast."));
-    ResolvedAst resolvedAst = compiler.backend.frontend.getResolvedAst(element);
+    ResolvedAst resolvedAst = element.resolvedAst;
     return new CodegenWorkItem.internal(resolvedAst, compilationContext);
   }