Parsed named expressions with Fasta.

pkg/analyzer/lib/src/fasta/ast_builder.dart

Index: pkg/analyzer/lib/src/fasta/ast_builder.dart
diff --git a/pkg/analyzer/lib/src/fasta/ast_builder.dart b/pkg/analyzer/lib/src/fasta/ast_builder.dart
index 14bd2894d59186a19d88f6947f58cf602754f291..1b5e3a9bbb00256fc7c28ff0479e4844b0dd9b5a 100644
--- a/pkg/analyzer/lib/src/fasta/ast_builder.dart
+++ b/pkg/analyzer/lib/src/fasta/ast_builder.dart
@@ -64,6 +64,14 @@ class AstBuilder extends ScopeListener {
     push(token);
   }
 
+  void handleNamedArgument(Token colon) {
+    debugEvent("NamedArgument");
+    Expression expression = pop();
+    SimpleIdentifier name = pop();
+    push(ast.namedExpression(
+        ast.label(name, toAnalyzerToken(colon)), expression));
+  }
+
   @override
   void handleNoConstructorReferenceContinuationAfterTypeArguments(Token token) {
     debugEvent("NoConstructorReferenceContinuationAfterTypeArguments");