[dce] remove `@:used` meta while collecting entrypoints

see #7805

src/core/meta.ml

@@ -183,6 +183,11 @@ let has m ml = List.exists (fun (m2,_,_) -> m = m2) ml
 let has_one_of ml1 ml2 = List.exists (fun (m2,_,_) -> List.mem m2 ml1) ml2
 let get m ml = List.find (fun (m2,_,_) -> m = m2) ml
 
+let rec remove m = function
+	| [] -> []
+	| (m2,_,_) :: l when m = m2 -> l
+	| x :: l -> x :: remove m l
+
 type meta_usage =
 	| TClass
 	| TClassField

src/optimization/dce.ml

@@ -672,7 +672,10 @@ let fix_accessors com =
 	) com.types
 
 let collect_entry_points dce com =
-	List.iter (fun t -> match t with
+	List.iter (fun t ->
+		let mt = t_infos t in
+		mt.mt_meta <- Meta.remove Meta.Used mt.mt_meta;
+		match t with
 		| TClassDecl c ->
 			let keep_class = keep_whole_class dce c && (not c.cl_extern || c.cl_interface) in
 			let loop stat cf =
@@ -880,10 +883,5 @@ let run com main mode =
 	) com.types;
 
 	(* cleanup added fields metadata - compatibility with compilation server *)
-	let rec remove_meta m = function
-		| [] -> []
-		| (m2,_,_) :: l when m = m2 -> l
-		| x :: l -> x :: remove_meta m l
-	in
-	List.iter (fun cf -> cf.cf_meta <- remove_meta Meta.Used cf.cf_meta) dce.marked_fields;
-	List.iter (fun cf -> cf.cf_meta <- remove_meta Meta.MaybeUsed cf.cf_meta) dce.marked_maybe_fields
+	List.iter (fun cf -> cf.cf_meta <- Meta.remove Meta.Used cf.cf_meta) dce.marked_fields;
+	List.iter (fun cf -> cf.cf_meta <- Meta.remove Meta.MaybeUsed cf.cf_meta) dce.marked_maybe_fields