add context save for GenerateFastApiCall

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index a1b04d55df7d59bfc576b0df692fce1c990d5cf2..9f8dafc234718ab73df9f9778bdf2e15163ddc5a 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -302,7 +302,7 @@ class MacroAssembler: public Assembler {
 
   // Leave the current exit frame. Expects/provides the return value in
   // register rax (untouched).
-  void LeaveApiExitFrame();
+  void LeaveApiExitFrame(bool restore_context);
 
   // Push and pop the registers that can hold pointers.
   void PushSafepointRegisters() { Pushad(); }
@@ -1280,7 +1280,8 @@ class MacroAssembler: public Assembler {
                                 Address thunk_address,
                                 Register thunk_last_arg,
                                 int stack_space,
-                                int return_value_offset_from_rbp);
+                                Operand return_value_operand,
+                                Operand* context_restore_operand);
 
   // Before calling a C-function from generated code, align arguments on stack.
   // After aligning the frame, arguments must be stored in rsp[0], rsp[8],
@@ -1436,7 +1437,7 @@ class MacroAssembler: public Assembler {
   // accessible via StackSpaceOperand.
   void EnterExitFrameEpilogue(int arg_stack_space, bool save_doubles);
 
-  void LeaveExitFrameEpilogue();
+  void LeaveExitFrameEpilogue(bool restore_context);
 
   // Allocation support helpers.
   // Loads the top of new-space into the result register.