Failure unpacking Emacs master tarball source [MSYS2/MINGW64]

[Angelo Graziosi]

With the last commit (3ad239e1bc1228407ae656440327a29e7373f977) I get:

$ wget http://git.savannah.gnu.org/cgit/emacs.git/snapshot/emacs-master.tar.gz

$ tar -xvof emacs-master.tar.gz
[...]
tar: emacs-master/test/src/emacs-resources/seccomp-filter.bpf: impossibile 
creare un collegamento simbolico a "../../../lib-src/seccomp-filter.bpf": No 
such file or directory
tar: emacs-master/test/src/emacs-resources/seccomp-filter-exec.bpf: impossibile 
creare un collegamento simbolico a "../../../lib-src/seccomp-filter-exec.bpf": 
No such file or directory
tar: Uscita con stato di fallimento in base agli errori precedenti

This breaks my script with which I have built Emacs for years..