sha512-crypt, and sha512.
(tests): Add sha256test, sha256c-test, sha512test, and sha512c-test.
(distribute): Add sha256.h and sha512.h.
* crypt/crypt-entry.c (crypt): Recognize the new $5$ and $6$ prefixes
and call the appropriate code.
* crypt/sha256-crypt.c: New file.
* crypt/sha256.c: New file.
* crypt/sha256.h: New file.
* crypt/sha256c-test.c: New file.
* crypt/sha256test.c: New file.
* crypt/sha512-crypt.c: New file.
* crypt/sha512.c: New file.
* crypt/sha512.h: New file.
* crypt/sha512c-test.c: New file.
* crypt/sha512test.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__thread_start):
Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__thread_start):
Likewise.