Avoid allocating an exception object in the snapshot reader.

runtime/vm/object_store.cc

Index: runtime/vm/object_store.cc
===================================================================
--- runtime/vm/object_store.cc	(revision 38227)
+++ runtime/vm/object_store.cc	(working copy)
@@ -132,6 +132,11 @@
     return false;
   }
   set_out_of_memory(Instance::Cast(result));
+
+  const UnhandledException& unhandled_exception = UnhandledException::Handle(
+      UnhandledException::New(Instance::Cast(result), Instance::Handle()));

[siva, 2014/07/16 01:00:13]

maybe add a comment here that the preallocated unhandled exception
object is initialized with the out of memory exception object to
make it clear.

[Florian Schneider, 2014/07/16 11:15:42]

Done.

+  set_preallocated_unhandled_exception(unhandled_exception);
+
   const Array& code_array = Array::Handle(
       isolate,
       Array::New(Stacktrace::kPreallocatedStackdepth, Heap::kOld));