make flags field wider (ints are easier to work with on many CPUs). * strace.c (trace): Split this function into two: collect_stopped_tcbs() and handle_stopped_tcbs(). Now we collect *all* waitable tasks, then handle them all, then repeat. Fixes RH#478419 "Some threads stop when strace with -f option is executed on a multi-thread process" * test/many_looping_threads.c: example program which cna't be straced successfully without this fix.