Revert of [heap] Remove size specializations in static object visitors.

src/heap/objects-visiting.cc

Index: src/heap/objects-visiting.cc
diff --git a/src/heap/objects-visiting.cc b/src/heap/objects-visiting.cc
index cf9fb5ed26210cee5972269ca33ec04195291dd8..a0df1f50c03800af72fbc0088accd4f3af3e6e4f 100644
--- a/src/heap/objects-visiting.cc
+++ b/src/heap/objects-visiting.cc
@@ -40,7 +40,8 @@
         return kVisitSlicedString;
 
       case kExternalStringTag:
-        return kVisitDataObject;
+        return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric,
+                                   instance_size, has_unboxed_fields);
 
       case kThinStringTag:
         return kVisitThinString;
@@ -96,7 +97,8 @@
       return kVisitSharedFunctionInfo;
 
     case JS_PROXY_TYPE:
-      return kVisitStruct;
+      return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric,
+                                 instance_size, has_unboxed_fields);
 
     case SYMBOL_TYPE:
       return kVisitSymbol;
@@ -164,19 +166,24 @@
     case JS_PROMISE_CAPABILITY_TYPE:
     case JS_PROMISE_TYPE:
     case JS_BOUND_FUNCTION_TYPE:
-      return has_unboxed_fields ? kVisitJSObject : kVisitJSObjectFast;
+      return GetVisitorIdForSize(kVisitJSObject, kVisitJSObjectGeneric,
+                                 instance_size, has_unboxed_fields);
     case JS_API_OBJECT_TYPE:
     case JS_SPECIAL_API_OBJECT_TYPE:
-      return kVisitJSApiObject;
+      return GetVisitorIdForSize(kVisitJSApiObject, kVisitJSApiObjectGeneric,
+                                 instance_size, has_unboxed_fields);
 
     case JS_FUNCTION_TYPE:
       return kVisitJSFunction;
 
     case FILLER_TYPE:
+      if (instance_size == kPointerSize) return kVisitDataObjectGeneric;
+    // Fall through.
     case FOREIGN_TYPE:
     case HEAP_NUMBER_TYPE:
     case MUTABLE_HEAP_NUMBER_TYPE:
-      return kVisitDataObject;
+      return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric,
+                                 instance_size, has_unboxed_fields);
 
     case FIXED_UINT8_ARRAY_TYPE:
     case FIXED_INT8_ARRAY_TYPE:
@@ -198,7 +205,8 @@
         return kVisitAllocationSite;
       }
 
-      return kVisitStruct;
+      return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric,
+                                 instance_size, has_unboxed_fields);
 
     default:
       UNREACHABLE();