Fix bundled static libraries

Author: bjorn3

src/archive.rs

@@ -159,6 +159,8 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
                         let err = err.to_string();
                         if err == "Unknown file magic" {
                             // Not an object file; skip it.
+                        } else if object::read::archive::ArchiveFile::parse(&*data).is_ok() {
+                            // Nested archive file; skip it.
                         } else {
                             sess.fatal(&format!(
                                 "error parsing `{}` during archive creation: {}",