Currently the spec mentions that division/modulo by 0 on integers results in 0 (i.e. x / 0 = 0 and x % 0 = 0).

I think it's important to clarify this for floats as well since at least SPIR-V's OpFRem (haven't looked at the behavior of other backends yet) seems to have undefined behavior if the 2nd operand is 0.