[turbofan] Spill rsi and rdi in their existing locations.

src/compiler/frame.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_FRAME_H_
 #define V8_COMPILER_FRAME_H_
 
 #include "src/bit-vector.h"
 #include "src/frames.h"
 
@@ skipping 118 matching lines @@
   }
 
   int ReserveSpillSlots(size_t slot_count) {
     DCHECK_EQ(0, spilled_callee_register_slot_count_);
     DCHECK_EQ(0, stack_slot_count_);
     stack_slot_count_ += static_cast<int>(slot_count);
     frame_slot_count_ += static_cast<int>(slot_count);
     return frame_slot_count_ - 1;
   }
 
+  static const int kContextSlot = 2;
+  static const int kJSFunctionSlot = 3;
+
  private:
   int AllocateAlignedFrameSlot(int width) {
     DCHECK(width == 4 || width == 8);
     // Skip one slot if necessary.
     if (width > kPointerSize) {
       DCHECK(width == kPointerSize * 2);
       frame_slot_count_++;
       frame_slot_count_ |= 1;
     }
     return frame_slot_count_++;
@@ skipping 33 matching lines @@
   int offset_;  // Encodes SP or FP in the low order bit.
 
   static const int kFromSp = 1;
   static const int kFromFp = 0;
 };
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_FRAME_H_