Set hasImplicitReturnType for variable initializer functions.

pkg/analyzer/lib/src/summary/resynthesize.dart

Index: pkg/analyzer/lib/src/summary/resynthesize.dart
diff --git a/pkg/analyzer/lib/src/summary/resynthesize.dart b/pkg/analyzer/lib/src/summary/resynthesize.dart
index f333826b7a384291a422eaeeeaed76669587e4f1..be97bfb0d091b1169d926c789a362dbf04581183 100644
--- a/pkg/analyzer/lib/src/summary/resynthesize.dart
+++ b/pkg/analyzer/lib/src/summary/resynthesize.dart
@@ -1764,11 +1764,6 @@ class _LibraryResynthesizer {
     }
     FunctionElementImpl initializerElement =
         buildLocalFunction(serializedInitializer);
-    // TODO(scheglov) The flag `hasImplicitReturnType` is `true` now because we
-    // don't serialize the return type. But once we do, the next two statements
-    // can be removed.
-    assert(initializerElement.hasImplicitReturnType == true);
-    initializerElement.hasImplicitReturnType = false;
     initializerElement.synthetic = true;
     variable.initializer = initializerElement;
   }