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

src/compiler/machine-operator.h

Index: src/compiler/machine-operator.h
diff --git a/src/compiler/machine-operator.h b/src/compiler/machine-operator.h
index a8a07fa695e890f9a7e5e56ded1d433c9018c911..796be2c3bbd888ac66646a23d7241d8784a78561 100644
--- a/src/compiler/machine-operator.h
+++ b/src/compiler/machine-operator.h
@@ -378,6 +378,10 @@ class MachineOperatorBuilder final : public ZoneObject {
   const Operator* Float64InsertLowWord32();
   const Operator* Float64InsertHighWord32();
 
+  // Change signalling NaN to quiet NaN.
+  // Identity for any input that is not signalling NaN.
+  const Operator* Float64SilenceNaN();
+
   // SIMD operators.
   const Operator* CreateFloat32x4();
   const Operator* Float32x4ExtractLane();