split api call stubs into accessor and function call stubs

src/x64/interface-descriptors-x64.cc

Index: src/x64/interface-descriptors-x64.cc
diff --git a/src/x64/interface-descriptors-x64.cc b/src/x64/interface-descriptors-x64.cc
index f19979d4674773b9664bec255b226fc7fdb98a81..86c92469c77834f038c360a52c9f9a0a0e90b946 100644
--- a/src/x64/interface-descriptors-x64.cc
+++ b/src/x64/interface-descriptors-x64.cc
@@ -301,6 +301,27 @@ void ApiFunctionDescriptor::Initialize(CallInterfaceDescriptorData* data) {
       rbx,  // call_data
       rcx,  // holder
       rdx,  // api_function_address
+      rdi,  // actual number of arguments
+  };
+  Representation representations[] = {
+      Representation::Tagged(),     // context
+      Representation::Tagged(),     // callee
+      Representation::Tagged(),     // call_data
+      Representation::Tagged(),     // holder
+      Representation::External(),   // api_function_address
+      Representation::Integer32(),  // actual number of arguments
+  };
+  data->Initialize(arraysize(registers), registers, representations);
+}
+
+
+void ApiAccessorDescriptor::Initialize(CallInterfaceDescriptorData* data) {
+  Register registers[] = {
+      rsi,  // context
+      rax,  // callee
+      rbx,  // call_data
+      rcx,  // holder
+      rdx,  // api_function_address
   };
   Representation representations[] = {
       Representation::Tagged(),    // context