+ Check for vec_ld instead of vec_mtvscr in the C AltiVec detection.
    + Include <altivec.h> in the C AltiVec detection.
  * modules/misc/memcpy/memcpyaltivec.c modules/video_chroma/i420_yuy2.c:
    + Include <altivec.h> in the C AltiVec versions.