Custom formatter cleanup Fix case where displaying a class constructor generated unreadable huge ou…

pkg/dev_compiler/test/codegen_expected/closure.js

 export const closure = Object.create(null);
 import { core, js, dart, dartx } from 'dart_sdk';
 let dynamic__Toint = () => (dynamic__Toint = dart.constFn(dart.functionType(core.int, [dart.dynamic], [dart.dynamic])))();
 let dynamic__Todynamic = () => (dynamic__Todynamic = dart.constFn(dart.functionType(dart.dynamic, [dart.dynamic], {y: core.String, z: dart.dynamic})))();
 let StringToList = () => (StringToList = dart.constFn(dart.functionType(core.List, [core.String])))();
 let ListOfint = () => (ListOfint = dart.constFn(core.List$(core.int)))();
 let dynamicTodynamic = () => (dynamicTodynamic = dart.constFn(dart.functionType(dart.dynamic, [dart.dynamic])))();
 let FnToListOfint = () => (FnToListOfint = dart.constFn(dart.functionType(ListOfint(), [dynamicTodynamic()])))();
 let MapOfMap$Map = () => (MapOfMap$Map = dart.constFn(core.Map$(core.Map, core.Map)))();
 let Foo = () => (Foo = dart.constFn(closure.Foo$()))();
@@ skipping 99 matching lines @@
     }, VoidToNull());
   },
   set closure(_) {}
 });
 /** @final {string} */
 closure.some_top_level_constant = "abc";
 /** @final {string} */
 closure.some_top_level_final = "abc";
 /** @type {string} */
 closure.some_top_level_var = "abc";
+dart.trackLibraries("closure", {"closure.dart": closure});