Make FastNewFunctionContextStub take slots parameter

src/mips/interface-descriptors-mips.cc

Index: src/mips/interface-descriptors-mips.cc
diff --git a/src/mips/interface-descriptors-mips.cc b/src/mips/interface-descriptors-mips.cc
index 3e22e696b26b8601ef5e282ab36e9e0bf319a578..4f009a488c08074594333e6337426626a2e90c08 100644
--- a/src/mips/interface-descriptors-mips.cc
+++ b/src/mips/interface-descriptors-mips.cc
@@ -20,6 +20,11 @@ void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
                                    default_stub_registers);
 }
 
+const Register FastNewFunctionContextDescriptor::FunctionRegister() {
+  return a1;
+}
+const Register FastNewFunctionContextDescriptor::SlotsRegister() { return a0; }
+
 const Register LoadDescriptor::ReceiverRegister() { return a1; }
 const Register LoadDescriptor::NameRegister() { return a2; }
 const Register LoadDescriptor::SlotRegister() { return a0; }
@@ -71,12 +76,6 @@ void FastNewClosureDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers, NULL);
 }
 
-void FastNewFunctionContextDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a1};
-  data->InitializePlatformSpecific(arraysize(registers), registers, NULL);
-}
-
 void FastNewObjectDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {a1, a3};