Hardware tests have shown that if the number of texgens/channels do not
match, you get garbage rendering. Presumably because the output
registers from the XF stage are fed into the incorrect input registers
for TEV/BP.
Currently, this causes Dolphin to crash/generate invalid shaders with an
assertion failure in the hardware backends. Instead, we log an error.
Perhaps in the future we should just spit out all texgens/colors anyway
from both stages, and let cross-stage optimization take care of DCE'ing
it away. But doing so would require changing the UIDs and invalidating
everyone's shader caches.
Stenzek
a9c1dcf656