Merged r2954:2955 from branches/SDL-1.2: Altivec alpha blitter alignment fix.

  Fixes Bugzilla #279.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%402260

src/video/SDL_blit_A.c

@@ -1341,7 +1341,7 @@ Blit32to32SurfaceAlphaAltivec(SDL_BlitInfo * info)
         ONE_PIXEL_BLEND((UNALIGNED_PTR(dstp)) && (width), width);
         if (width > 0) {
             int extrawidth = (width % 4);
-            vector unsigned char valigner = vec_lvsl(0, srcp);
+            vector unsigned char valigner = VEC_ALIGNER(srcp);
             vector unsigned char vs = (vector unsigned char) vec_ld(0, srcp);
             width -= extrawidth;
             while (width) {