[turbofan] Introduce JSCallForwardVarargs operator.

src/arm/interface-descriptors-arm.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.
 
 #include "src/arm/interface-descriptors-arm.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/interface-descriptors.h"
 
@@ skipping 161 matching lines @@
 
 
 void CallTrampolineDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // r0 : number of arguments
   // r1 : the target to call
   Register registers[] = {r1, r0};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
+void CallForwardVarargsDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  // r2 : start index (to support rest parameters)
+  // r1 : the target to call
+  Register registers[] = {r1, r2};
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
 
 void ConstructStubDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // r0 : number of arguments
   // r1 : the target to call
   // r3 : the new target
   // r2 : allocation site or undefined
   Register registers[] = {r1, r3, r0, r2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
@@ skipping 235 matching lines @@
       r1,  // the JSGeneratorObject to resume
       r2   // the resume mode (tagged)
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM