[BasicAA] Account for wrapping when using abs(Scale*V0 + (-Scale)*V1) >= abs(Scale) (#137755)
Similar to 1b7ef6aac8a3cad245c0ed14fe21725e31261f73, add a check to only
set MinAbsVarIndex if abs(Scale*V0) and abs((-Scale)*V1) won't wrap. In
the absence of IsNSW, try to use the bitwidths of the original V and
Scale to rule out wrapping