[stubs] An easier way of defining a stub call interface descriptor.

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 3ab31a0ab78b549014f27ee31338f4af86768cc2..ca6c1179210996d24791fe598ac72f4ad8f00552 100644
--- a/src/s390/interface-descriptors-s390.cc
+++ b/src/s390/interface-descriptors-s390.cc
@@ -11,6 +11,15 @@ namespace internal {
 
 const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
 
+void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
+    CallInterfaceDescriptorData* data, int register_parameter_count) {
+  const Register default_stub_registers[] = {r2, r3, r4, r5, r6};
+  CHECK_LE(static_cast<size_t>(register_parameter_count),
+           arraysize(default_stub_registers));
+  data->InitializePlatformSpecific(register_parameter_count,
+                                   default_stub_registers);
+}
+
 const Register LoadDescriptor::ReceiverRegister() { return r3; }
 const Register LoadDescriptor::NameRegister() { return r4; }
 const Register LoadDescriptor::SlotRegister() { return r2; }