tests: check decoding of oldfstat, oldlstat, and oldstat syscalls

tests: check decoding of oldfstat, oldlstat, and oldstat syscalls

* tests/oldfstat.c: New file.
* tests/oldlstat.c: Likewise.
* tests/oldstat.c: Likewise.
* tests/oldfstat.test: New test.
* tests/oldlstat.test: Likewise.
* tests/oldstat.test: Likewise.
* tests/xstatx.c [!OLD_STAT]: define OLD_STAT to 0.
(print_stat) [OLD_STAT]: Print predefined values for
st_blksize/st_blocks.
(print_stat): Check for !OLD_STAT in nanosecond precision checks.
(main) [OLD_STAT]: Ignore EOVERFLOW.
(main): Test for successful rc in returned size value check;
print address only on non-successful rc.
* tests/.gitignore: Add oldfstat, oldlstat, and oldstat.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add oldfstat.test, oldlstat.test, and oldstat.test.