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 d831c618b714e739831577d9f3a3fb68df5af78e..4410692d863f9a03ca568981e9cbdf6ef675f061 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -619,6 +619,13 @@ 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());