[jak3] Fix crash with shadow in precursor ship

[water111]

When the dp-bipedals get blown up by the nuke gun, their bones go to NaNs on the last frame. The shadow renderer doesn't handle this well and draws all possible triangles as single tris. This overflows the vif unpack field and triggered an assert when sizes inside the shadow renderer weren't consistent.

My guess is that this works on the real game either because:

• their shadow renderer draws garbage data, but you can't tell because the screen is white from the nuke
• no NaN on PS2 means that the shadow renderer behaved differently, not using all single tris.

As a workaround, if the bones are NaN, the shadow renderer treats them as 0, meaning there is no shadow drawn.

[xTVaser]

Hopefully also fixes #3009 but that was always difficult to reproduce