Set the current context to the function's context when entering to LAP.

src/x64/macro-assembler-x64.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_X64_MACRO_ASSEMBLER_X64_H_
 #define V8_X64_MACRO_ASSEMBLER_X64_H_
 
 #include "src/bailout-reason.h"
 #include "src/base/flags.h"
 #include "src/frames.h"
@@ skipping 1332 matching lines @@
   void NegativeZeroTest(CodeGenerator* cgen,
                         Register result,
                         Register op,
                         JumpTarget* then_target);
 
   // Check if result is zero and any of op1 and op2 are negative.
   // Register scratch is destroyed, and it must be different from op2.
   void NegativeZeroTest(Register result, Register op1, Register op2,
                         Register scratch, Label* then_label);
 
+  // Machine code version of Map::GetConstructor().
+  // |temp| holds |result|'s map when done.
+  void GetMapConstructor(Register result, Register map, Register temp);
+
   // Find the function context up the context chain.
   void LoadContext(Register dst, int context_chain_length);
 
   // Load the global object from the current context.
   void LoadGlobalObject(Register dst) {
     LoadNativeContextSlot(Context::EXTENSION_INDEX, dst);
   }
 
   // Load the global proxy from the current context.
   void LoadGlobalProxy(Register dst) {
@@ skipping 317 matching lines @@
 inline Operand StackOperandForReturnAddress(int32_t disp) {
   return Operand(rsp, disp);
 }
 
 #define ACCESS_MASM(masm) masm->
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_