Encapsulate megamorphic load/tail-call in hydrogen

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index b9f4e52997a65a0bc64367ee8ec0f699b00d9244..1272bad55e32760c79dfd279fdf7870582be3c8f 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -585,6 +585,13 @@ void VectorKeyedLoadStub::InitializeInterfaceDescriptor(
 }
 
 
+void MegamorphicLoadStub::InitializeInterfaceDescriptor(
+    CodeStubInterfaceDescriptor* descriptor) {
+  LoadDescriptor call_descriptor(isolate());
+  descriptor->Initialize(MajorKey(), call_descriptor);
+}
+
+
 void FastNewClosureStub::InitializeInterfaceDescriptor(
     CodeStubInterfaceDescriptor* descriptor) {
   FastNewClosureDescriptor call_descriptor(isolate());
@@ -1015,6 +1022,13 @@ void KeyedLoadGenericStub::InstallDescriptors(Isolate* isolate) {
 
 
 // static
+void MegamorphicLoadStub::InstallDescriptors(Isolate* isolate) {
+  MegamorphicLoadStub stub(isolate, LoadIC::State(CONTEXTUAL));
+  InstallDescriptor(isolate, &stub);
+}
+
+
+// static
 void StoreFieldStub::InstallDescriptors(Isolate* isolate) {
   StoreFieldStub stub(isolate, FieldIndex::ForInObjectOffset(0),
                       Representation::None());