Handle #[unsafe(no_mangle)]

Author: simonask

csbindgen/src/parser.rs

@@ -123,7 +123,7 @@ fn parse_method(item: FnItem, options: &BindgenOptions) -> Option<ExternMethod>
             .iter()
             .map(|attr| {
                 let name = &attr.path().segments.last().unwrap().ident;
-                if name == "no_mangle" {
+                if name == "no_mangle" || name == "unsafe(no_mangle)" {
                     return Some(NoMangle);
                 } else if name == "export_name" {
                     if let Some(x) = get_str_from_meta(&attr.meta) {