Make compile-time errors catchable

runtime/vm/clustered_snapshot.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/clustered_snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 95 matching lines @@
   }
 
   void WriteClass(Serializer* s, RawClass* cls) {
     Snapshot::Kind kind = s->kind();
     RawObject** from = cls->from();
     RawObject** to = cls->to_snapshot(kind);
     for (RawObject** p = from; p <= to; p++) {
       s->WriteRef(*p);
     }
     intptr_t class_id = cls->ptr()->id_;
+    ASSERT(class_id != kIllegalCid);
     s->WriteCid(class_id);
     s->Write<int32_t>(cls->ptr()->instance_size_in_words_);
     s->Write<int32_t>(cls->ptr()->next_field_offset_in_words_);
     s->Write<int32_t>(cls->ptr()->type_arguments_field_offset_in_words_);
     s->Write<uint16_t>(cls->ptr()->num_type_arguments_);
     s->Write<uint16_t>(cls->ptr()->num_own_type_arguments_);
     s->Write<uint16_t>(cls->ptr()->num_native_fields_);
     s->WriteTokenPosition(cls->ptr()->token_pos_);
     s->Write<uint16_t>(cls->ptr()->state_bits_);
   }
@@ skipping 4993 matching lines @@
 
   deserializer.ReadVMSnapshot();
 
   Dart::set_instructions_snapshot_buffer(instructions_buffer_);
   Dart::set_data_snapshot_buffer(data_buffer_);
 
   return ApiError::null();
 }
 
 }  // namespace dart