This patch intends to unify both strcpy and stpcpy implementationsi
for PPC64 and PPC64/POWER7. The idead default powerpc64 implementation
is to provide both doubleword and word aligned memory access.
For PPC64/POWER7 is also provide doubleword and word memory access,
remove the branch hints, use the cmpb instruction for compare
doubleword/words, and add an optimization for inputs of same alignment.
