* sysdeps/x86_64/dl-machine.h (elf_machine_runtime_setup): Declare
external functions with hidden attribute.
(elf_machine_rela): Optimize.
* sysdeps/x86_64/memset.S: New file.
* sysdeps/x86_64/bzero.S: New file.
* sysdeps/x86_64/stpcpy.S: New file.
* sysdeps/x86_64/strcat.S: New file.
* sysdeps/x86_64/strchr.S: New file.
* sysdeps/x86_64/strcpy.S: New file.
* sysdeps/x86_64/strcspn.S: New file.
* sysdeps/x86_64/strlen.S: New file.
* sysdeps/x86_64/strpbrk.S: New file.
* sysdeps/x86_64/strspn.S: New file.
* sysdeps/x86_64/strcmp.S: New file.
* sysdeps/x86_64/strtok_r.S: New file.
* sysdeps/x86_64/strtok.S: New file.
* sysdeps/x86_64/memcpy.S: New file.
* sysdeps/x86_64/mempcpy.S: New file.