Set and keep parent function of signature functions.

runtime/vm/kernel_binary_flowgraph.cc

Index: runtime/vm/kernel_binary_flowgraph.cc
diff --git a/runtime/vm/kernel_binary_flowgraph.cc b/runtime/vm/kernel_binary_flowgraph.cc
index 1ab259c8f098cc0bad596c4ad4490e90c4d3497b..85fdcb3701393fa9c97bb6000de28011eab48922 100644
--- a/runtime/vm/kernel_binary_flowgraph.cc
+++ b/runtime/vm/kernel_binary_flowgraph.cc
@@ -1480,8 +1480,9 @@ void StreamingDartTypeTranslator::BuildFunctionType(bool simple) {
   TypeParameterScope scope(this, first_item_offest, list_length);
 
   Function& signature_function = Function::ZoneHandle(
-      Z, Function::NewSignatureFunction(*active_class_->klass,
-                                        TokenPosition::kNoSource));
+      Z,
+      Function::NewSignatureFunction(*active_class_->klass, Function::Handle(),

[rmacnak, 2017/06/21 20:10:00]

Handle(Z)

[regis, 2017/06/21 20:14:01]

Done.

+                                     TokenPosition::kNoSource));
 
   intptr_t required_count;
   intptr_t all_count;