Revert of [turbofan] Restore basic write barrier elimination.

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 389e6c4ae53cf96ebf69279fe50e4d9761a1bdbc..0828441c1d6001bed01aa425d1a7a73ef491d7af 100644
--- a/src/compiler/simplified-operator.h
+++ b/src/compiler/simplified-operator.h
@@ -25,9 +25,8 @@
 class Operator;
 struct SimplifiedOperatorGlobalCache;
 
-enum BaseTaggedness : uint8_t { kUntaggedBase, kTaggedBase };
-
-size_t hash_value(BaseTaggedness);
+
+enum BaseTaggedness { kUntaggedBase, kTaggedBase };
 
 std::ostream& operator<<(std::ostream&, BaseTaggedness);
 
@@ -64,7 +63,6 @@
   MaybeHandle<Name> name;         // debugging only.
   Type* type;                     // type of the field.
   MachineType machine_type;       // machine type of the field.
-  WriteBarrierKind write_barrier_kind;  // write barrier hint.
 
   int tag() const { return base_is_tagged == kTaggedBase ? kHeapObjectTag : 0; }
 };
@@ -88,7 +86,6 @@
   int header_size;                // size of the header, without tag.
   Type* type;                     // type of the element.
   MachineType machine_type;       // machine type of the element.
-  WriteBarrierKind write_barrier_kind;  // write barrier hint.
 
   int tag() const { return base_is_tagged == kTaggedBase ? kHeapObjectTag : 0; }
 };