fix #29182, generate top level const fields lazily

pkg/dev_compiler/test/codegen_expected/node_modules.js

Index: pkg/dev_compiler/test/codegen_expected/node_modules.js
diff --git a/pkg/dev_compiler/test/codegen_expected/node_modules.js b/pkg/dev_compiler/test/codegen_expected/node_modules.js
index 4d542183f0118c6e9a53c05aefc83aeaf33f3fb1..0425cf75235336328bf338ac73f7569ca69a484b 100644
--- a/pkg/dev_compiler/test/codegen_expected/node_modules.js
+++ b/pkg/dev_compiler/test/codegen_expected/node_modules.js
@@ -29,18 +29,23 @@ dart.fn(node_modules.f, VoidTodynamic());
 node_modules._f = function() {
 };
 dart.fn(node_modules._f, VoidTodynamic());
-node_modules.constant = "abc";
-node_modules.finalConstant = "abc";
 dart.defineLazy(node_modules, {
+  get constant() {
+    return "abc";
+  },
+  get finalConstant() {
+    return "abc";
+  },
   get lazy() {
     return dart.fn(() => {
       core.print('lazy');
       return "abc";
     }, VoidToString())();
-  }
-});
-node_modules.mutable = "abc";
-dart.defineLazy(node_modules, {
+  },
+  get mutable() {
+    return "abc";
+  },
+  set mutable(_) {},
   get lazyMutable() {
     return dart.fn(() => {
       core.print('lazyMutable');