PPC64: [turbofan] Fix DCHECK in AssembleSwap.

src/compiler/ppc/code-generator-ppc.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/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/ppc/macro-assembler-ppc.h"
@@ skipping 1362 matching lines @@
       DCHECK(destination->IsStackSlot());
       MemOperand dst = g.ToMemOperand(destination);
       __ mr(temp, src);
       __ LoadP(src, dst);
       __ StoreP(temp, dst);
     }
 #if V8_TARGET_ARCH_PPC64
   } else if (source->IsStackSlot() || source->IsDoubleStackSlot()) {
 #else
   } else if (source->IsStackSlot()) {
+    DCHECK(destination->IsStackSlot());
 #endif
-    DCHECK(destination->IsStackSlot());
     Register temp_0 = kScratchReg;
     Register temp_1 = r0;
     MemOperand src = g.ToMemOperand(source);
     MemOperand dst = g.ToMemOperand(destination);
     __ LoadP(temp_0, src);
     __ LoadP(temp_1, dst);
     __ StoreP(temp_0, dst);
     __ StoreP(temp_1, src);
   } else if (source->IsDoubleRegister()) {
     DoubleRegister temp = kScratchDoubleReg;
@@ skipping 57 matching lines @@
     }
   }
   MarkLazyDeoptSite();
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8