Uninitialized reads in date-1 in busybox

[mchalupa]

The date-1 benchmark in busybox contains an uninitialized read on several paths. One path is again because the bb_show_usage function does not abort the program. The other path arises probably due to the approximation of modeling the posix environment. Here is a test harness that you can use to reproduce the issues (compile the harness with date-1.i and -fsanitize=memory).
harness.zip