Add support of ignore tag for json.marshal

core/encoding/json/marshal.odin

@@ -406,7 +406,7 @@ marshal_to_writer :: proc(w: io.Writer, v: any, opt: ^Marshal_Options) -> (err:
 			ti := runtime.type_info_base(type_info_of(v.id))
 			info := ti.variant.(runtime.Type_Info_Struct)
 			first_iteration := true
-			for name, i in info.names {
+			fields_loop: for name, i in info.names {
 				omitempty := false
 
 				json_name, extra := json_name_from_tag_value(reflect.struct_tag_get(reflect.Struct_Tag(info.tags[i]), "json"))
@@ -414,6 +414,8 @@ marshal_to_writer :: proc(w: io.Writer, v: any, opt: ^Marshal_Options) -> (err:
 					switch flag {
 					case "omitempty":
 						omitempty = true
+					case "ignore":
+						continue fields_loop
 					}
 				}