[turbofan] Add the StackSlot operator to turbofan.

src/compiler/pipeline.h

 // 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.
 
 #ifndef V8_COMPILER_PIPELINE_H_
 #define V8_COMPILER_PIPELINE_H_
 
 // Clients of this interface shouldn't depend on lots of compiler internals.
 // Do not include anything from src/compiler here!
 #include "src/compiler.h"
@@ skipping 56 matching lines @@
   void Run(Arg0 arg_0);
 
   CompilationInfo* info() const { return info_; }
   Isolate* isolate() { return info_->isolate(); }
 
   void BeginPhaseKind(const char* phase_kind);
   void RunPrintAndVerify(const char* phase, bool untyped = false);
   Handle<Code> ScheduleAndGenerateCode(CallDescriptor* call_descriptor);
   void AllocateRegisters(const RegisterConfiguration* config,
                          CallDescriptor* descriptor, bool run_verifier);
+
+  void InitializeFrame(CallDescriptor* descriptor);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_PIPELINE_H_