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

pkg/dev_compiler/tool/input_sdk/private/js_helper.dart

Index: pkg/dev_compiler/tool/input_sdk/private/js_helper.dart
diff --git a/pkg/dev_compiler/tool/input_sdk/private/js_helper.dart b/pkg/dev_compiler/tool/input_sdk/private/js_helper.dart
index a20547be96933a84537807eec275f4455c90661b..8b53cc602b879f520335707ff13d292ab19027c4 100644
--- a/pkg/dev_compiler/tool/input_sdk/private/js_helper.dart
+++ b/pkg/dev_compiler/tool/input_sdk/private/js_helper.dart
@@ -25,6 +25,8 @@ part 'regexp_helper.dart';
 part 'string_helper.dart';
 part 'js_rti.dart';
 
+final _identityHashCode = JS('', 'Symbol("_identityHashCode")');
+
 class _Patch {
   const _Patch();
 }
@@ -57,10 +59,10 @@ class Primitives {
   }
 
   static int objectHashCode(object) {
-    int hash = JS('int|Null', r'#.$identityHash', object);
+    int hash = JS('int|Null', r'#[#]', object, _identityHashCode);
     if (hash == null) {
       hash = JS('int', '(Math.random() * 0x3fffffff) | 0');
-      JS('void', r'#.$identityHash = #', object, hash);
+      JS('void', r'#[#] = #', object, _identityHashCode, hash);
     }
     return JS('int', '#', hash);
   }