Merge branch 'cleanup' into 'master'

tests/Makefile

tests/alloca.c

tests/args.c

tests/arpainet.c

tests/assert.c

tests/constructor.c

tests/ctype.c

tests/destructor.c

tests/dirent/main.c

tests/dirent/scandir.c

tests/error.c

tests/expected/libgen.stdout

tests/expected/stdio/all.stdout

tests/expected/stdio/fseek.stdout

tests/expected/stdio/popen.stdout

tests/expected/stdlib/rand.stdout

tests/expected/string/strrchr.stdout

tests/expected/unistd/brk.stdout

tests/expected/unistd/fchdir.stdout

tests/expected/unistd/fsync.stdout