* linux-nat.c (linux_nat_resume): In non-stop, also only tag
resumed LWPs as resumed.
(linux_nat_wait_1): If there's no resumed LWP in the set of LWPs
we're waiting for, bail out with TARGET_WAITKIND_IGNORE, instead
of throwing an internal error. If an LWP of a process we're not
waiting for reports a signal, don't force collecting a SIGSTOP,
and if it was breakpoint hit in non-stop mode, cancel it. Don't
go through all LWPs cancelling breakpoints in non-stop mode.
(resume_stopped_resumed_lwps): New.
(linux_nat_wait): Use it.