Fix generation of variable initializer synthetic functions in summary AST linker.

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

Index: pkg/analyzer/lib/src/summary/link.dart
diff --git a/pkg/analyzer/lib/src/summary/link.dart b/pkg/analyzer/lib/src/summary/link.dart
index 87af2c0a22a6ed992dce8d3ac63d7f0bbbb83873..5f05a50938787a8b068c3282a691512bf206d0a2 100644
--- a/pkg/analyzer/lib/src/summary/link.dart
+++ b/pkg/analyzer/lib/src/summary/link.dart
@@ -4584,7 +4584,7 @@ abstract class VariableElementForLink
 
   @override
   FunctionElementForLink_Initializer get initializer {
-    if (unlinkedVariable.constExpr == null) {
+    if (unlinkedVariable.initializer == null) {
       return null;
     } else {
       return _initializer ??= new FunctionElementForLink_Initializer(this);