Stop using strerror(3) in rtld, which brings in msgcat and stdio.
Directly access sys_errlist array of errno messages with private
rtld_strerror() function.
Now,
$ size /libexec/ld-elf.so.1
text data bss dec hex filename
96983 2480 8744 108207 1a6af /libexec/ld-elf.so.1
Reviewed by: dim, kan
MFC after: 2 weeks