Support for NamedExpression(s) as constructor initializer arguments.

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 15b712d6eb7ecd5cd47051c360eece0de799eb98..324d83dee4d8f8b4c07a993789f17a0fbfb1345c 100644
--- a/pkg/analyzer/lib/src/summary/resynthesize.dart
+++ b/pkg/analyzer/lib/src/summary/resynthesize.dart
@@ -283,9 +283,15 @@ class _ConstExprBuilder {
 
   _ConstExprBuilder(this.resynthesizer, this.uc);
 
-  Expression get expr => stack.single;
-
   Expression build() {
+    Expression expr = _build();
+    if (uc.name.isNotEmpty) {
+      return AstFactory.namedExpression2(uc.name, expr);
+    }
+    return expr;
+  }
+
+  Expression _build() {
     if (!uc.isValidConst) {
       return AstFactory.identifier3(r'$$invalidConstExpr$$');
     }