[$] Year-2038 work in 4.18

We now have less than 20 years to wait until the time_t value usedon 32-bit systems will overflow and create time-related mayhem across theplanet. The grand plan for solving thisproblem was posted over three years ago now; progress since then hasseemed slow. But quite a bit of work has happened deep inside the kerneland, in 4.18, some of the first work that will be visible to user space hasbeen merged. The year-2038 problem is not yet solved, but things aremoving in that direction.