[runtime] Optimize and unify rest parameters.

src/arm64/interface-descriptors-arm64.cc

Index: src/arm64/interface-descriptors-arm64.cc
diff --git a/src/arm64/interface-descriptors-arm64.cc b/src/arm64/interface-descriptors-arm64.cc
index 460c9eb3d335b97db83962f30765d04170653905..9d941fdb4969abe3ec16d29229545971914d8058 100644
--- a/src/arm64/interface-descriptors-arm64.cc
+++ b/src/arm64/interface-descriptors-arm64.cc
@@ -65,11 +65,6 @@ const Register ArgumentsAccessNewDescriptor::parameter_count() { return x2; }
 const Register ArgumentsAccessNewDescriptor::parameter_pointer() { return x3; }
 
 
-const Register RestParamAccessDescriptor::parameter_count() { return x2; }
-const Register RestParamAccessDescriptor::parameter_pointer() { return x3; }
-const Register RestParamAccessDescriptor::rest_parameter_index() { return x4; }
-
-
 const Register ApiGetterDescriptor::function_address() { return x2; }
 
 
@@ -99,6 +94,14 @@ void FastNewContextDescriptor::InitializePlatformSpecific(
 }
 
 
+void FastNewRestParameterDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  // x1: function
+  Register registers[] = {x1};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
+
 void ToNumberDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // x0: value