The existing implementation of bzero incorrectly clears bytes when the
start address is not word aligned. Fix it by using REG_SHI macro which
works on both 32 and 64 bit.
Submitted by: Artem Belevich (fbsdlist at src cx)
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
