[turbofan] Prevent storing signalling NaNs into holey double arrays.

src/compiler/x64/code-generator-x64.cc

 // Copyright 2013 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/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 1527 matching lines @@
       __ vpsllq(kScratchDoubleReg, kScratchDoubleReg, 63);
       if (instr->InputAt(0)->IsFPRegister()) {
         __ vxorpd(i.OutputDoubleRegister(), kScratchDoubleReg,
                   i.InputDoubleRegister(0));
       } else {
         __ vxorpd(i.OutputDoubleRegister(), kScratchDoubleReg,
                   i.InputOperand(0));
       }
       break;
     }
+    case kSSEFloat64SilenceNaN:
+      __ Xorpd(kScratchDoubleReg, kScratchDoubleReg);
+      __ Subsd(i.InputDoubleRegister(0), kScratchDoubleReg);
+      break;
     case kX64Movsxbl:
       ASSEMBLE_MOVX(movsxbl);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movzxbl:
       ASSEMBLE_MOVX(movzxbl);
       __ AssertZeroExtended(i.OutputRegister());
       break;
     case kX64Movb: {
       size_t index = 0;
@@ skipping 769 matching lines @@
     int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
     __ Nop(padding_size);
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8