use bit fields for class state and field type values. This shrinks the snapshot

vm/raw_object_snapshot.cc

Index: vm/raw_object_snapshot.cc
===================================================================
--- vm/raw_object_snapshot.cc	(revision 10677)
+++ vm/raw_object_snapshot.cc	(working copy)
@@ -54,13 +54,7 @@
     cls.set_next_field_offset(reader->ReadIntptrValue());
     cls.set_num_native_fields(reader->ReadIntptrValue());
     cls.set_token_pos(reader->ReadIntptrValue());
-    cls.set_class_state(reader->Read<int8_t>());
-    if (reader->Read<bool>()) {
-      cls.set_is_const();
-    }
-    if (reader->Read<bool>()) {
-      cls.set_is_interface();
-    }
+    cls.set_state_bits(reader->Read<uint8_t>());
 
     // Set all the object fields.
     // TODO(5411462): Need to assert No GC can happen here, even though
@@ -100,9 +94,7 @@
     writer->WriteIntptrValue(ptr()->next_field_offset_);
     writer->WriteIntptrValue(ptr()->num_native_fields_);
     writer->WriteIntptrValue(ptr()->token_pos_);
-    writer->Write<int8_t>(ptr()->class_state_);
-    writer->Write<bool>(ptr()->is_const_);
-    writer->Write<bool>(ptr()->is_interface_);
+    writer->Write<uint8_t>(ptr()->state_bits_);
 
     // Write out all the object pointer fields.
     SnapshotWriterVisitor visitor(writer);
@@ -538,10 +530,7 @@
 
   // Set all non object fields.
   field.set_token_pos(reader->ReadIntptrValue());
-  field.set_is_static(reader->Read<bool>());
-  field.set_is_final(reader->Read<bool>());
-  field.set_is_const(reader->Read<bool>());
-  field.set_has_initializer(reader->Read<bool>());
+  field.set_kind_bits(reader->Read<uint8_t>());
 
   // Set all the object fields.
   // TODO(5411462): Need to assert No GC can happen here, even though
@@ -571,10 +560,7 @@
 
   // Write out all the non object fields.
   writer->WriteIntptrValue(ptr()->token_pos_);
-  writer->Write<bool>(ptr()->is_static_);
-  writer->Write<bool>(ptr()->is_final_);
-  writer->Write<bool>(ptr()->is_const_);
-  writer->Write<bool>(ptr()->has_initializer_);
+  writer->WriteIntptrValue(ptr()->kind_bits_);
 
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);