[runtime] Optimize and unify rest parameters.

src/ia32/interface-descriptors-ia32.cc

Index: src/ia32/interface-descriptors-ia32.cc
diff --git a/src/ia32/interface-descriptors-ia32.cc b/src/ia32/interface-descriptors-ia32.cc
index b3dae2deeb2646df8b93571a167381e077afad2c..b99f6801e3698b9139bfde342895ee89ba5bf97e 100644
--- a/src/ia32/interface-descriptors-ia32.cc
+++ b/src/ia32/interface-descriptors-ia32.cc
@@ -68,11 +68,6 @@ const Register ArgumentsAccessNewDescriptor::parameter_count() { return ecx; }
 const Register ArgumentsAccessNewDescriptor::parameter_pointer() { return edx; }
 
 
-const Register RestParamAccessDescriptor::parameter_count() { return ecx; }
-const Register RestParamAccessDescriptor::parameter_pointer() { return edx; }
-const Register RestParamAccessDescriptor::rest_parameter_index() { return ebx; }
-
-
 const Register ApiGetterDescriptor::function_address() { return edx; }
 
 
@@ -102,6 +97,13 @@ void FastNewContextDescriptor::InitializePlatformSpecific(
 }
 
 
+void FastNewRestParameterDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {edi};
+  data->InitializePlatformSpecific(arraysize(registers), registers, NULL);
+}
+
+
 void ToNumberDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // ToNumberStub invokes a function, and therefore needs a context.