[turbofan] Fix double register swap in ARM and ARM64 backends.

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 819 matching lines @@
     __ Str(temp_0, dst);
     __ Str(temp_1, src);
   } else if (source->IsDoubleRegister()) {
     UseScratchRegisterScope scope(masm());
     FPRegister temp = scope.AcquireD();
     FPRegister src = g.ToDoubleRegister(source);
     if (destination->IsDoubleRegister()) {
       FPRegister dst = g.ToDoubleRegister(destination);
       __ Fmov(temp, src);
       __ Fmov(src, dst);
-      __ Fmov(src, temp);
+      __ Fmov(dst, temp);
     } else {
       DCHECK(destination->IsDoubleStackSlot());
       MemOperand dst = g.ToMemOperand(destination, masm());
       __ Fmov(temp, src);
       __ Ldr(src, dst);
       __ Str(temp, dst);
     }
   } else {
     // No other combinations are possible.
     UNREACHABLE();
   }
 }
 
 
 void CodeGenerator::AddNopForSmiCodeInlining() { __ movz(xzr, 0); }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8