Thank you for your patch. This has been applied in libtool:
 
https://git.savannah.gnu.org/cgit/libtool.git/commit/?h=development&id=2048edd2cba086b194bd30901e5fe552a4890680

-- 
Ileana Dumitrescu

GPG Public Key: FA26 CA78 4BE1 8892 7F22 B99F 6570 EA01 146F 7354