[runtime] Optimize and unify rest parameters.

src/arm/interface-descriptors-arm.cc

Index: src/arm/interface-descriptors-arm.cc
diff --git a/src/arm/interface-descriptors-arm.cc b/src/arm/interface-descriptors-arm.cc
index eaa8524b66c89629268d7c874516e085583faa7c..c805c2996e4799f2966b7667bbd7c897be46da6e 100644
--- a/src/arm/interface-descriptors-arm.cc
+++ b/src/arm/interface-descriptors-arm.cc
@@ -65,11 +65,6 @@ const Register ArgumentsAccessNewDescriptor::parameter_count() { return r2; }
 const Register ArgumentsAccessNewDescriptor::parameter_pointer() { return r3; }
 
 
-const Register RestParamAccessDescriptor::parameter_count() { return r2; }
-const Register RestParamAccessDescriptor::parameter_pointer() { return r3; }
-const Register RestParamAccessDescriptor::rest_parameter_index() { return r4; }
-
-
 const Register ApiGetterDescriptor::function_address() { return r2; }
 
 
@@ -99,6 +94,13 @@ void FastNewContextDescriptor::InitializePlatformSpecific(
 }
 
 
+void FastNewRestParameterDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {r1};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
+
 void ToNumberDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {r0};