I’m having trouble understanding `Base.Math.rem_pio2_kernel`

.

Consider the following:

```
julia> const rempio2 = Base.Math.rem_pio2_kernel
rem_pio2_kernel (generic function with 2 methods)
julia> rempio2(0.0)
(-1, Base.Math.DoubleFloat64(1.5707963267948966, 6.12323399538461e-17))
julia> rempio2(nextfloat(0.0))
(1, Base.Math.DoubleFloat64(-1.5707963267948966, -6.12323399538461e-17))
julia> rempio2(prevfloat(0.0))
(-1, Base.Math.DoubleFloat64(1.5707963267948966, 6.12323399538461e-17))
julia> rempio2(10000.0)
(6366, Base.Math.DoubleFloat64(0.310583623688122, -5.7722118981828364e-18))
julia> rempio2(1e8)
(1, Base.Math.DoubleFloat64(0.3718988077091178, 2.2854919533097746e-17))
```

Everything seems OK until the last one; I was expecting the first entry to be `1e8 / (pi/2)`

approximately.