Update FATE reference due to WAVE channel mask now being set correctly.

This removes warnings about strict aliasing violations.
Signed-off-by: Mans Rullgard <mans@mansr.com>

The third argument of OP_U8_ALTIVEC is evaluated at most once so
there is no need for a potentially unused temporary variable.
Signed-off-by: Mans Rullgard <mans@mansr.com>

This flag is no longer used.
Signed-off-by: Mans Rullgard <mans@mansr.com>

An assembler able to cope with AVX instructions is now required.