[turbofan] Use MachineRepresentation for PropertyCell access.

src/compiler/access-builder.h

Index: src/compiler/access-builder.h
diff --git a/src/compiler/access-builder.h b/src/compiler/access-builder.h
index 50932ce06010efeaf7ea73c2eb0cbae03cea40c4..b1d858afbc07da18dcfc3b86eeec02c4143c9df2 100644
--- a/src/compiler/access-builder.h
+++ b/src/compiler/access-builder.h
@@ -195,10 +195,6 @@ class AccessBuilder final : public AllStatic {
   // Provides access to Context slots.
   static FieldAccess ForContextSlot(size_t index);
 
-  // Provides access to PropertyCell::value() field.
-  static FieldAccess ForPropertyCellValue();
-  static FieldAccess ForPropertyCellValue(Type* type);
-
   // Provides access to FixedArray elements.
   static ElementAccess ForFixedArrayElement();
   static ElementAccess ForFixedArrayElement(ElementsKind kind);