Simplify canonicalization of constants and types.

runtime/vm/raw_object_snapshot.cc

Index: runtime/vm/raw_object_snapshot.cc
===================================================================
--- runtime/vm/raw_object_snapshot.cc	(revision 1045)
+++ runtime/vm/raw_object_snapshot.cc	(working copy)
@@ -39,8 +39,6 @@
     // Set all non object fields.
     cls.set_instance_size(reader->Read<intptr_t>());
     cls.set_type_arguments_instance_field_offset(reader->Read<intptr_t>());
-    cls.set_num_constants(reader->Read<intptr_t>());
-    cls.set_num_canonical_types(reader->Read<intptr_t>());
     cls.set_next_field_offset(reader->Read<intptr_t>());
     cls.set_num_native_fields(reader->Read<intptr_t>());
     cls.set_class_state(reader->Read<int8_t>());
@@ -83,8 +81,6 @@
     writer->Write<ObjectKind>(ptr()->instance_kind_);
     writer->Write<intptr_t>(ptr()->instance_size_);
     writer->Write<intptr_t>(ptr()->type_arguments_instance_field_offset_);
-    writer->Write<intptr_t>(ptr()->num_constants_);
-    writer->Write<intptr_t>(ptr()->num_canonical_types_);
     writer->Write<intptr_t>(ptr()->next_field_offset_);
     writer->Write<intptr_t>(ptr()->num_native_fields_);
     writer->Write<int8_t>(ptr()->class_state_);