Buffers make more sense for this function because one of their primary
use cases is working with bytes.
The tuple implementation was an array of floats, which is less
performant and ergonomic for common operations. (i.e: bit manipulation)
Buffers also have the advantage they are mutable, meaning the user
can write ints to an existing buffer.
Previously int/to-number would fail if the input was outside
the range of an int32.
Because Janet numbers are doubles,
they can safely store larger ints than an int32.
This commit updates int/to-number to restrict the
value to the range of integers a double can hold, instead of an int32.
(int/to-number value) converts an s64 or u64 to a number.
It restricts the value to the int32 range,
so that `int32?` will always suceeded when called on the result.
