Reload: Don't free the saved class table while another thread may be reading it.

runtime/vm/class_table.cc

Index: runtime/vm/class_table.cc
diff --git a/runtime/vm/class_table.cc b/runtime/vm/class_table.cc
index ed2ea00cc39c8e939a36a6493235a040a8a4718d..334bca9c2f974122eb5a16edc1d995f4d463f744 100644
--- a/runtime/vm/class_table.cc
+++ b/runtime/vm/class_table.cc
@@ -83,6 +83,12 @@ ClassTable::~ClassTable() {
 }
 
 
+void ClassTable::AddOldTable(RawClass** old_table) {
+  ASSERT(Thread::Current()->IsMutatorThread());
+  old_tables_->Add(old_table);
+}
+
+
 void ClassTable::FreeOldTables() {
   while (old_tables_->length() > 0) {
     free(old_tables_->RemoveLast());