Prepare for chaining resynthesizers from AC to SDK AC.

pkg/analyzer/test/src/summary/resynthesize_test.dart

Index: pkg/analyzer/test/src/summary/resynthesize_test.dart
diff --git a/pkg/analyzer/test/src/summary/resynthesize_test.dart b/pkg/analyzer/test/src/summary/resynthesize_test.dart
index 11fcaf73b66252e648221f797dbffb32e7714889..4c73bc17355e2ae747f106f89e04477c9a257736 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_test.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_test.dart
@@ -77,10 +77,14 @@ class ResynthTest extends ResolverTestCase {
       compareFunctionElements(
           resynthesized.entryPoint, original.entryPoint, '(entry point)');
     }
-    compareExecutableElements(
-        resynthesized.loadLibraryFunction as ExecutableElementImpl,
-        original.loadLibraryFunction as ExecutableElementImpl,
-        '(loadLibraryFunction)');
+    // The libraries `dart:core` and `dart:async` cannot create their
+    // `loadLibrary` functions until after both are created.
+    if (original.name != 'dart.core' && original.name != 'dart.async') {
+      compareExecutableElements(
+          resynthesized.loadLibraryFunction as ExecutableElementImpl,
+          original.loadLibraryFunction as ExecutableElementImpl,
+          '(loadLibraryFunction)');
+    }
     // TODO(paulberry): test metadata.
   }