Convert between tagged and untagged kSimd128 values.

src/compiler/simplified-operator.h

Index: src/compiler/simplified-operator.h
diff --git a/src/compiler/simplified-operator.h b/src/compiler/simplified-operator.h
index 6b8ea4bbe19c58cde847dd5d47ed6fb95e0877ea..413bff90dab38409ade00267f3d3d791908216a9 100644
--- a/src/compiler/simplified-operator.h
+++ b/src/compiler/simplified-operator.h
@@ -164,6 +164,11 @@ class SimplifiedOperatorBuilder final : public ZoneObject {
   const Operator* ChangeFloat64ToTagged();
   const Operator* ChangeBoolToBit();
   const Operator* ChangeBitToBool();
+#define SIMD128_CHANGE(TYPE, Type, type, lane_count, lane_type) \
+  const Operator* ChangeTaggedTo##Type();                       \
+  const Operator* Change##Type##ToTagged();
+  SIMD128_TYPES(SIMD128_CHANGE)
+#undef SIMD128_CHANGE
 
   const Operator* ObjectIsNumber();
   const Operator* ObjectIsReceiver();