[turbofan] use double temp registers for stack-stack swap on arm64

src/compiler/arm64/code-generator-arm64.cc

 // 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.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/arm64/macro-assembler-arm64.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 941 matching lines @@
       __ Mov(dst, temp);
     } else {
       DCHECK(destination->IsStackSlot());
       MemOperand dst = g.ToMemOperand(destination, masm());
       __ Mov(temp, src);
       __ Ldr(src, dst);
       __ Str(temp, dst);
     }
   } else if (source->IsStackSlot() || source->IsDoubleStackSlot()) {
     UseScratchRegisterScope scope(masm());
-    CPURegister temp_0 = scope.AcquireX();
-    CPURegister temp_1 = scope.AcquireX();
+    DoubleRegister temp_0 = scope.AcquireD();
+    DoubleRegister temp_1 = scope.AcquireD();
     MemOperand src = g.ToMemOperand(source, masm());
     MemOperand dst = g.ToMemOperand(destination, masm());
     __ Ldr(temp_0, src);
     __ Ldr(temp_1, dst);
     __ Str(temp_0, dst);
     __ Str(temp_1, src);
   } else if (source->IsDoubleRegister()) {
     UseScratchRegisterScope scope(masm());
     FPRegister temp = scope.AcquireD();
     FPRegister src = g.ToDoubleRegister(source);
@@ skipping 39 matching lines @@
     }
   }
   MarkLazyDeoptSite();
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8