[heap] Limit friendship of the Heap class to essentials.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index aa49b99b54a2d743afc822433319ef1eab3aa873..501a517d782b7ed0a7305dc65ef14ca5ee8b8167 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -622,14 +622,6 @@ class Factory final {
   PUBLIC_SYMBOL_LIST(SYMBOL_ACCESSOR)
 #undef SYMBOL_ACCESSOR
 
-  inline void set_string_table(Handle<StringTable> table) {
-    isolate()->heap()->set_string_table(*table);
-  }
-
-  inline void set_weak_stack_trace_list(Handle<WeakFixedArray> list) {
-    isolate()->heap()->set_weak_stack_trace_list(*list);
-  }
-
   // Allocates a new SharedFunctionInfo object.
   Handle<SharedFunctionInfo> NewSharedFunctionInfo(
       Handle<String> name, int number_of_literals, FunctionKind kind,