Fix handle sharing bug in implementation of shape changes.

runtime/vm/isolate_reload.cc

Index: runtime/vm/isolate_reload.cc
diff --git a/runtime/vm/isolate_reload.cc b/runtime/vm/isolate_reload.cc
index a00f05e75700ae3baa0892b051a398c71ea9d759..bc4263e1d342229d90a7ab34ab197b6f40168a7b 100644
--- a/runtime/vm/isolate_reload.cc
+++ b/runtime/vm/isolate_reload.cc
@@ -48,7 +48,9 @@ DEFINE_FLAG(bool, check_reloaded, false,
 
 
 InstanceMorpher::InstanceMorpher(Zone* zone, const Class& from, const Class& to)
-  : from_(from), to_(to), mapping_(zone, 0) {
+    : from_(Class::Handle(zone, from.raw())),
+      to_(Class::Handle(zone, to.raw())),
+      mapping_(zone, 0) {
   ComputeMapping();
   before_ = new(zone) ZoneGrowableArray<const Instance*>(zone, 0);
   after_ = new(zone) ZoneGrowableArray<const Instance*>(zone, 0);