X87: [crankshaft] Support ES6 tail call elimination.

src/crankshaft/x87/lithium-codegen-x87.h

 // 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.
 
 #ifndef V8_CRANKSHAFT_X87_LITHIUM_CODEGEN_X87_H_
 #define V8_CRANKSHAFT_X87_LITHIUM_CODEGEN_X87_H_
 
 #include <map>
 
 #include "src/ast/scopes.h"
@@ skipping 201 matching lines @@
     CallRuntime(function, function->nargs, instr);
   }
 
   void CallRuntimeFromDeferred(Runtime::FunctionId id,
                                int argc,
                                LInstruction* instr,
                                LOperand* context);
 
   void LoadContextFromDeferred(LOperand* context);
 
-  // Generate a direct call to a known function.  Expects the function
+  void PrepareForTailCall(const ParameterCount& actual, Register scratch1,
+                          Register scratch2, Register scratch3);
+
+  // Generate a direct call to a known function. Expects the function
   // to be in edi.
   void CallKnownFunction(Handle<JSFunction> function,
                          int formal_parameter_count, int arity,
-                         LInstruction* instr);
+                         bool is_tail_call, LInstruction* instr);
 
   void RecordSafepointWithLazyDeopt(LInstruction* instr,
                                     SafepointMode safepoint_mode);
 
   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
                                             Safepoint::DeoptMode mode);
   void DeoptimizeIf(Condition cc, LInstruction* instr,
                     Deoptimizer::DeoptReason deopt_reason,
                     Deoptimizer::BailoutType bailout_type);
   void DeoptimizeIf(Condition cc, LInstruction* instr,
@@ skipping 249 matching lines @@
   Label* external_exit_;
   Label done_;
   int instruction_index_;
   LCodeGen::X87Stack x87_stack_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CRANKSHAFT_X87_LITHIUM_CODEGEN_X87_H_