[Clang][counted_by] Add support for 'counted_by' on struct pointers

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -6710,10 +6710,13 @@ def err_counted_by_attr_pointee_unknown_size : Error<
     "%select{|. This will be an error in a future compiler version}3"
     ""
   "}2">;
+def err_count_attr_func_cannot_be_a_call : Error<"function must not be a call">;
+def err_count_attr_func_must_have_one_param
+    : Error<"function must have only one parameter">;
 
-def warn_counted_by_attr_elt_type_unknown_size :
-  Warning<err_counted_by_attr_pointee_unknown_size.Summary>,
-  InGroup<BoundsSafetyCountedByEltTyUnknownSize>;
+def warn_counted_by_attr_elt_type_unknown_size
+    : Warning<err_counted_by_attr_pointee_unknown_size.Summary>,
+      InGroup<BoundsSafetyCountedByEltTyUnknownSize>;
 
 // __builtin_counted_by_ref diagnostics:
 def err_builtin_counted_by_ref_must_be_flex_array_member : Error<