mkfifoat() is available in Android only after API 23. We can't use tar's
implementation of mkfifioat() since it will use tar's implementation of
mknodat(). This will cause infinite recursion in file gnu/at-func.c and
segfault.

Snippet of backtrace:
....
#9  0x000000555559819c in mknodat (fd=-100, file=0x7fb7c90050 "sda", mode=25008, dev=2048) at /home/builder/.termux-build/tar/src/gnu/at-func.c:75
#10 0x000000555559819c in mknodat (fd=-100, file=0x7fb7c90050 "sda", mode=25008, dev=2048) at /home/builder/.termux-build/tar/src/gnu/at-func.c:75
#11 0x000000555559819c in mknodat (fd=-100, file=0x7fb7c90050 "sda", mode=25008, dev=2048) at /home/builder/.termux-build/tar/src/gnu/at-func.c:75
#12 0x000000555559819c in mknodat (fd=-100, file=0x7fb7c90050 "sda", mode=25008, dev=2048) at /home/builder/.termux-build/tar/src/gnu/at-func.c:75
#13 0x000000555556a9d4 in extract_node (file_name=0x7fb7c90050 "sda", typeflag=52) at /home/builder/.termux-build/tar/src/src/extract.c:1447
#14 0x0000005555568f38 in extract_archive () at /home/builder/.termux-build/tar/src/src/extract.c:1709
....

diff -uNr tar-1.30/src/extract.c tar-1.30.mod/src/extract.c
--- tar-1.30/src/extract.c	2017-12-16 23:23:12.000000000 +0200
+++ tar-1.30.mod/src/extract.c	2017-12-25 14:31:31.541886176 +0200
@@ -42,6 +42,11 @@
 # define fchown(fd, uid, gid) (errno = ENOSYS, -1)
 #endif
 
+static int
+mkfifoat(int fd, const char* path, mode_t mode) {
+  return mknodat(fd, path, (mode & ~S_IFMT) | S_IFIFO, 0);
+}
+
 /* Return true if an error number ERR means the system call is
    supported in this case.  */
 static bool