Create and cache method extraction stub in the ICData.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 40fc1b7d493c1cd948df846dd8975645efac5334..4f01d1be8c06db23de2394cc637f934dc6ed9913 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -3220,6 +3220,37 @@ void Function::set_closure_allocation_stub(const Code& value) const {
 }
 
 
+RawFunction* Function::method_extractor() const {
+  ASSERT(IsImplicitClosureFunction());
+  const Object& obj = Object::Handle(raw_ptr()->data_);
+  ASSERT(!obj.IsNull());
+  return ClosureData::Cast(obj).method_extractor();
+}
+
+
+void Function::set_method_extractor(const Function& value) const {
+  ASSERT(IsImplicitClosureFunction());
+  const Object& obj = Object::Handle(raw_ptr()->data_);
+  ASSERT(!obj.IsNull());
+  ClosureData::Cast(obj).set_method_extractor(value);
+}
+
+
+RawFunction* Function::extracted_method_closure() const {
+  ASSERT(kind() == RawFunction::kMethodExtractor);
+  const Object& obj = Object::Handle(raw_ptr()->data_);
+  ASSERT(obj.IsFunction());
+  return Function::Cast(obj).raw();
+}
+
+
+void Function::set_extracted_method_closure(const Function& value) const {
+  ASSERT(kind() == RawFunction::kMethodExtractor);
+  ASSERT(raw_ptr()->data_ == Object::null());
+  set_data(value);
+}
+
+
 RawFunction* Function::parent_function() const {
   if (IsClosureFunction()) {
     const Object& obj = Object::Handle(raw_ptr()->data_);
@@ -4309,6 +4340,9 @@ const char* Function::ToCString() const {
     case RawFunction::kConstImplicitGetter:
       kind_str = " const-getter";
       break;
+    case RawFunction::kMethodExtractor:
+      kind_str = " method-extractor";
+      break;
     default:
       UNREACHABLE();
   }
@@ -4342,6 +4376,13 @@ void ClosureData::set_closure_allocation_stub(const Code& value) const {
 }
 
 
+void ClosureData::set_method_extractor(const Function& value) const {
+  ASSERT(!value.IsNull());
+  ASSERT(raw_ptr()->method_extractor_ == Function::null());
+  StorePointer(&raw_ptr()->method_extractor_, value.raw());
+}
+
+
 void ClosureData::set_parent_function(const Function& value) const {
   StorePointer(&raw_ptr()->parent_function_, value.raw());
 }