When canonicalize instances check if all fields are canonical. If a field is a non-canonical number…

runtime/vm/snapshot.cc

Index: runtime/vm/snapshot.cc
===================================================================
--- runtime/vm/snapshot.cc	(revision 23823)
+++ runtime/vm/snapshot.cc	(working copy)
@@ -793,7 +793,8 @@
     if (kind_ == Snapshot::kFull) {
       result->SetCreatedFromSnapshot();
     } else if (result->IsCanonical()) {
-      *result = result->Canonicalize();
+      *result = result->CheckAndCanonicalize(NULL);
+      ASSERT(!result->IsNull());
     }
     return result->raw();
   }