It seems GAS makes the substitution automatically, but Clang's
integrated assembler does not (yet). It fails with "invalid operand for
instruction."
Reported by: sbruno
Update libc assembly code to use macros that work on both o32 and n64.
Merge string functions from NetBSD.
The changes are from http://svn.freebsd.org/base/user/jmallett/octeon
Approved by: rrs (mentor), jmallett