[es6] Re-implement rest parameters via desugaring.

src/compiler/linkage.cc

 // Copyright 2014 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/code-stubs.h"
 #include "src/compiler.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/frame.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/node.h"
@@ skipping 210 matching lines @@
     case Runtime::kFinalizeClassDefinition:        // TODO(conradw): Is it safe?
     case Runtime::kDefineClassMethod:              // TODO(jarin): Is it safe?
     case Runtime::kDefineGetterPropertyUnchecked:  // TODO(jarin): Is it safe?
     case Runtime::kDefineSetterPropertyUnchecked:  // TODO(jarin): Is it safe?
     case Runtime::kForInDone:
     case Runtime::kForInStep:
     case Runtime::kGetOriginalConstructor:
     case Runtime::kNewArguments:
     case Runtime::kNewClosure:
     case Runtime::kNewFunctionContext:
-    case Runtime::kNewRestParamSlow:
     case Runtime::kPushBlockContext:
     case Runtime::kPushCatchContext:
     case Runtime::kReThrow:
     case Runtime::kStringCompare:
     case Runtime::kStringEquals:
     case Runtime::kToFastProperties:  // TODO(jarin): Is it safe?
     case Runtime::kTraceEnter:
     case Runtime::kTraceExit:
       return 0;
     case Runtime::kInlineArguments:
@@ skipping 278 matching lines @@
     return LinkageLocation::ForCalleeFrameSlot(spill_index);
   } else {
     // Parameter. Use the assigned location from the incoming call descriptor.
     int parameter_index = 1 + index;  // skip index 0, which is the target.
     return incoming_->GetInputLocation(parameter_index);
   }
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8