Remember isFieldFormal informative flag in VariableDeclaration(s).

pkg/compiler/lib/src/kernel/kernel_debug.dart

Index: pkg/compiler/lib/src/kernel/kernel_debug.dart
diff --git a/pkg/compiler/lib/src/kernel/kernel_debug.dart b/pkg/compiler/lib/src/kernel/kernel_debug.dart
index 261aa093874a0d6b09d55297a48af4fec039b5b8..a61a77a2ad03905ac935eb0dee331aeac790bed5 100644
--- a/pkg/compiler/lib/src/kernel/kernel_debug.dart
+++ b/pkg/compiler/lib/src/kernel/kernel_debug.dart
@@ -52,7 +52,8 @@ class DebugPrinter extends Visitor with Indentation, Tagging<Node> {
     openNode(node, '${node.runtimeType}', {
       'name': '${node.name ?? '--unnamed--'}',
       'isFinal': '${node.isFinal}',
-      'isConst': '${node.isConst}'
+      'isConst': '${node.isConst}',
+      'isFieldFormal': '${node.isFieldFormal}'
     });
     node.visitChildren(this);
     closeNode();