Wrong hashes for some `Rational`s

On Julia v1.10.0-alpha1 and master, some `Rational`s which are equal have different hashes:
```julia
julia> hash(5//2) # same hash as on older Julia versions (≥ v1.6)
0x16b7f40fdbb2c57d

julia> hash(Int128(5)//2) # the same hash is also obtained for UInt128(5)//2 and BigInt(5)//2
0xb795033f6f2a0674
```