Fix context register allocation in LTransitionElementsKind.

src/x64/lithium-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 2248 matching lines @@
     HTransitionElementsKind* instr) {
   LOperand* object = UseRegister(instr->object());
   if (IsSimpleMapChangeTransition(instr->from_kind(), instr->to_kind())) {
     LOperand* object = UseRegister(instr->object());
     LOperand* new_map_reg = TempRegister();
     LOperand* temp_reg = TempRegister();
     LTransitionElementsKind* result = new(zone()) LTransitionElementsKind(
         object, NULL, new_map_reg, temp_reg);
     return result;
   } else {
-    LOperand* context = UseAny(instr->context());
+    LOperand* context = UseFixed(instr->context(), rsi);
     LTransitionElementsKind* result =
         new(zone()) LTransitionElementsKind(object, context, NULL, NULL);
     return AssignPointerMap(result);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoTrapAllocationMemento(
     HTrapAllocationMemento* instr) {
   LOperand* object = UseRegister(instr->object());
@@ skipping 343 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64