[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 6a06f25eaec69fb6c59e1d20cfb7e97b1373148e..7cc1fe18bd03104c8eafe51cf21ca15e319ddacf 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 ContextExtension fields.
   static FieldAccess ForContextExtensionScopeInfo();
   static FieldAccess ForContextExtensionExtension();