Fix issue with context not being saved on x64 introduced in 144543004

src/x64/stub-cache-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 503 matching lines @@
   __ PopReturnAddressTo(scratch1);
 
   ASSERT(!holder.is(rsi));
   // context save
   __ push(rsi);
 
   // Get the function and setup the context.
   Handle<JSFunction> function = optimization.constant_function();
   __ Move(scratch2, function);
   __ push(scratch2);
+  __ movp(rsi, FieldOperand(scratch2, JSFunction::kContextOffset));
 
   Isolate* isolate = masm->isolate();
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
   Handle<Object> call_data(api_call_info->data(), isolate);
   // Push data from ExecutableAccessorInfo.
   bool call_data_undefined = false;
   if (isolate->heap()->InNewSpace(*call_data)) {
     __ Move(scratch2, api_call_info);
     __ movp(scratch3, FieldOperand(scratch2, CallHandlerInfo::kDataOffset));
   } else if (call_data->IsUndefined()) {
@@ skipping 1577 matching lines @@
   // -----------------------------------
   TailCallBuiltin(masm, Builtins::kKeyedLoadIC_Miss);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64