VM: Restore old implementation of ClassID.cid* fields

runtime/lib/class_id.dart

Index: runtime/lib/class_id.dart
diff --git a/runtime/lib/class_id.dart b/runtime/lib/class_id.dart
index 8a8d670cf90e1f1549769d614d8074cb3b4c52e4..2f60f8559c00bb6f594a828148186a116513404b 100644
--- a/runtime/lib/class_id.dart
+++ b/runtime/lib/class_id.dart
@@ -5,13 +5,5 @@
 class ClassID {
   static int getID(Object value) native "ClassID_getID";
 
-  static int _lookup(String name) native "ClassID_byName";
-
-  static final int cidArray = _lookup('Array');
-  static final int cidExternalOneByteString = _lookup('ExternalOneByteString');
-  static final int cidGrowableObjectArray = _lookup('GrowableObjectArray');
-  static final int cidImmutableArray = _lookup('ImmutableArray');
-  static final int cidOneByteString = _lookup('OneByteString');
-  static final int cidTwoByteString = _lookup('TwoByteString');
-  static final int cidBigint = _lookup('Bigint');
+  // VM injects class id constants into this class.
 }