Function IsMultipleOf8

cpp/src/arrow/util/bit_util.h:75–75

constexpr bool IsMultipleOf64(int64_t n) { return (n & 63) == 0; }

constexpr bool IsMultipleOf8(int64_t n) { return (n & 7) == 0; }

// Returns a mask for the bit_index lower order bits.
// Valid in the range `[0, 8*sizof(Uint)]` if `kAllowUpperBound`