License rust and c source files

services/libs/typeflags/src/flag_set.rs

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: MPL-2.0
+
 use itertools::Itertools;
 use proc_macro2::{Ident, TokenStream};
 use quote::{quote, TokenStreamExt};

services/libs/typeflags/src/lib.rs

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: MPL-2.0
+
 //！This crate defines the procedural macro typeflags to implement capability for Asterinas.
 //! When using this crate, typeflags-util should also be added as dependency.
 //! This is due to typeflgas is a proc-macro crate, which is only allowed to export proc-macro interfaces.

services/libs/typeflags/src/type_flag.rs

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: MPL-2.0
+
 use proc_macro2::TokenStream;
 use quote::quote;
 use syn::{

services/libs/typeflags/src/util.rs

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: MPL-2.0
+
 use proc_macro2::{Ident, TokenStream};
 use quote::{quote, TokenStreamExt};