[turbofan] Add the StackSlot operator to turbofan.

src/compiler/instruction-scheduler.cc

 // Copyright 2015 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/compiler/instruction-scheduler.h"
 
 #include "src/base/adapters.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 187 matching lines @@
       return kIsBlockTerminator;
 
     case kCheckedLoadInt8:
     case kCheckedLoadUint8:
     case kCheckedLoadInt16:
     case kCheckedLoadUint16:
     case kCheckedLoadWord32:
     case kCheckedLoadWord64:
     case kCheckedLoadFloat32:
     case kCheckedLoadFloat64:
+    case kArchStackSlot:

[titzer, 2016/01/28 15:17:02]

Technically this is not a load, since it just computes the address of the stack
slot.

       return kIsLoadOperation;
 
     case kCheckedStoreWord8:
     case kCheckedStoreWord16:
     case kCheckedStoreWord32:
     case kCheckedStoreWord64:
     case kCheckedStoreFloat32:
     case kCheckedStoreFloat64:
     case kArchStoreWithWriteBarrier:
       return kHasSideEffect;
@@ skipping 53 matching lines @@
       }
     }
 
     node->set_total_latency(max_latency + node->latency());
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8