Handle default formal parameters in LocalElementBuilder

pkg/analyzer/test/src/context/context_test.dart

Index: pkg/analyzer/test/src/context/context_test.dart
diff --git a/pkg/analyzer/test/src/context/context_test.dart b/pkg/analyzer/test/src/context/context_test.dart
index d5f9766faa3e3d9bfc9a575795bd258be8608e0f..a3d979ea00668b35d458dfe792b6e09bdfea760a 100644
--- a/pkg/analyzer/test/src/context/context_test.dart
+++ b/pkg/analyzer/test/src/context/context_test.dart
@@ -2461,6 +2461,10 @@ class ClassOne {
 class ClassTwo {
   // Implicit no-argument constructor
 }
+
+void topLevelFunctionWithLocalFunction() {
+  void localFunction({bool b: false}) {}
+}
 ''');
     context.resolveCompilationUnit2(source, source);
     LibraryElement firstElement = context.computeLibraryElement(source);