[runtime] Optimize and unify rest parameters.

src/x64/interface-descriptors-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 45 matching lines @@
 
 const Register ArgumentsAccessReadDescriptor::index() { return rdx; }
 const Register ArgumentsAccessReadDescriptor::parameter_count() { return rax; }
 
 
 const Register ArgumentsAccessNewDescriptor::function() { return rdi; }
 const Register ArgumentsAccessNewDescriptor::parameter_count() { return rcx; }
 const Register ArgumentsAccessNewDescriptor::parameter_pointer() { return rdx; }
 
 
-const Register RestParamAccessDescriptor::parameter_count() { return rcx; }
-const Register RestParamAccessDescriptor::parameter_pointer() { return rdx; }
-const Register RestParamAccessDescriptor::rest_parameter_index() { return rbx; }
-
-
 const Register ApiGetterDescriptor::function_address() { return r8; }
 
 
 const Register MathPowTaggedDescriptor::exponent() { return rdx; }
 
 
 const Register MathPowIntegerDescriptor::exponent() {
   return MathPowTaggedDescriptor::exponent();
 }
 
 
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return rax; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return rbx; }
 
 
 void FastNewClosureDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {rbx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
 
 void FastNewContextDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {rdi};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
 
+void FastNewRestParameterDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {rdi};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
+
 void TypeofDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {rbx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
 
 void ToNumberDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // ToNumberStub invokes a function, and therefore needs a context.
@@ skipping 324 matching lines @@
       r15,  // address of first argument (argv)
       rbx   // the runtime function to call
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64