htl: Enable more tests

htl: Enable more tests

* nptl/tst-_res1.c, tst-_res1mod1.c, tst-_res1mod2.c, tst-atfork2.c,
tst-atfork2mod.c, tst-fini1.c, tst-fini1mod.c, tst-tls4.c, tst-tls4moda.c,
tst-tls4modb.c: Move to...
* sysdeps/pthread: ... here.  Rename tst-tls4.c to tst-pt-tls4.c to avoid
conflicting with elf/tst-tls4.c.
* nptl/Makefile: Move corresponding references and rules to...
* sysdeps/pthread/Makefile: ... here.