tests: replace old stat tests with stat.test and stat64.test

tests: replace old stat tests with stat.test and stat64.test

* tests/stat.c: Replace with a wrapper around lstatx.c
* tests/stat.test: Replace with a wrapper around statx.sh.
* tests/stat32-v.test: Remove.
* tests/stat32.c: Remove.
* tests/stat64-v.test: Remove.
* tests/stat64.c: New file.
* tests/stat64.test: New test.
* tests/Makefile.am (check_PROGRAMS): Replace stat32 with stat64.
(stat_CFLAGS): Rename to stat64_CFLAGS.
(TESTS): Replace stat32-v.test and stat64-v.test with stat64.test.
* tests/.gitignore: Replace stat32 with stat64.