Revert of Rework CallApi*Stubs.

src/s390/interface-descriptors-s390.cc

Index: src/s390/interface-descriptors-s390.cc
diff --git a/src/s390/interface-descriptors-s390.cc b/src/s390/interface-descriptors-s390.cc
index 5c6dda055617b6033e1e93db14d06d4f818ccbfd..600d521b04c02dadf68ef5d37d5f05fbb0c31bbe 100644
--- a/src/s390/interface-descriptors-s390.cc
+++ b/src/s390/interface-descriptors-s390.cc
@@ -334,13 +334,25 @@
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ApiCallbackDescriptorBase::InitializePlatformSpecific(
+void ApiFunctionDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r2,  // callee
       r6,  // call_data
       r4,  // holder
       r3,  // api_function_address
+      r5,  // actual number of arguments
+  };
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
+void ApiAccessorDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {
+      r2,  // callee
+      r6,  // call_data
+      r4,  // holder
+      r3,  // api_function_address
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }