Rework CallApi*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 333486ad8a4221329aecb92af9018a1ab16de40f..f724e5d48a112ebdf1e10f5be266087299de9e2e 100644
--- a/src/x64/interface-descriptors-x64.cc
+++ b/src/x64/interface-descriptors-x64.cc
@@ -381,21 +381,7 @@ void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-
-void ApiFunctionDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      rdi,  // callee
-      rbx,  // call_data
-      rcx,  // holder
-      rdx,  // api_function_address
-      rax,  // actual number of arguments
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-
-void ApiAccessorDescriptor::InitializePlatformSpecific(
+void ApiCallbackDescriptorBase::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       rdi,  // callee