Using SubtypeTestCache object instead of an array, that way we do not need to patch and can communi…

runtime/vm/raw_object_snapshot.cc

Index: runtime/vm/raw_object_snapshot.cc
===================================================================
--- runtime/vm/raw_object_snapshot.cc	(revision 7292)
+++ runtime/vm/raw_object_snapshot.cc	(working copy)
@@ -1073,6 +1073,22 @@
 }
 
 
+RawSubtypeTestCache* SubtypeTestCache::ReadFrom(SnapshotReader* reader,
+                                                intptr_t object_id,
+                                                intptr_t tags,
+                                                Snapshot::Kind kind) {
+  UNREACHABLE();
+  return NULL;
+}
+
+
+void RawSubtypeTestCache::WriteTo(SnapshotWriter* writer,
+                                  intptr_t object_id,
+                                  Snapshot::Kind kind) {
+  UNREACHABLE();
+}
+
+
 RawError* Error::ReadFrom(SnapshotReader* reader,
                           intptr_t object_id,
                           intptr_t tags,