The AltiVec blitters don't compile, since they require __VEC__ to be enabled in
order for the compiler to understand "vector" and friends (i.e. do AltiVec)
But you don't want to turn AltiVec on globally, since then the code would only
run on a G4 (there are already runtime tests, before using the AltiVec
variants)

The solution here is to enable AltiVec locally, for the actual AltiVec code.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401754