[turbofan] Enable tail calls for %_CallFunction.

src/compiler/linkage.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_LINKAGE_H_
 #define V8_COMPILER_LINKAGE_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/frame.h"
 #include "src/compiler/machine-type.h"
 #include "src/compiler/operator.h"
 #include "src/frames.h"
 #include "src/runtime/runtime.h"
 #include "src/zone.h"
 
 namespace v8 {
 namespace internal {
 
 class CallInterfaceDescriptor;
 
 namespace compiler {
 
+class Node;
 class OsrHelper;
 
 // Describes the location for a parameter or a return value to a call.
 class LinkageLocation {
  public:
   explicit LinkageLocation(int location) : location_(location) {}
 
   bool is_register() const {
     return 0 <= location_ && location_ <= ANY_REGISTER;
   }
@@ skipping 127 matching lines @@
 
   // Get the callee-saved FP registers, if any, across this call.
   RegList CalleeSavedFPRegisters() const { return callee_saved_fp_registers_; }
 
   const char* debug_name() const { return debug_name_; }
 
   bool UsesOnlyRegisters() const;
 
   bool HasSameReturnLocationsAs(const CallDescriptor* other) const;
 
+  bool CanTailCall(const Node* call) const;
+
  private:
   friend class Linkage;
 
   const Kind kind_;
   const MachineType target_type_;
   const LinkageLocation target_loc_;
   const MachineSignature* const machine_sig_;
   const LocationSignature* const location_sig_;
   const size_t js_param_count_;
   const Operator::Properties properties_;
@@ skipping 89 matching lines @@
   CallDescriptor* const incoming_;
 
   DISALLOW_COPY_AND_ASSIGN(Linkage);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_LINKAGE_H_