* elf/dl-close.c [USE_TLS && TLS_TCB_AT_TP] (_dl_close): Reimplement
tracking of freed memory in static TLS block.
* elf/Makefile: Add rules to build and run tst-tls13.
* elf/tst-tls13.c: New file.
* elf/tst-tlsmod13.c: New file.
* elf/tst-tlsmod13a.c: New file.
* elf/tst-tls8.c: Adjust types of variables to avoid warnings.