[lldb][plugin] Use counter directly for number of readers (#139252)

Here we were initializing & locking a shared_mutex in a thread, while
releasing it in the parent which may/often turned out to be a different
thread (shared_mutex::unlock_shared is undefined behavior if called from
a thread that doesn't hold the lock).

Switch to counter to more simply keep track of number of readers and
simply lock/unlock rather than utilizing reader mutex to verify last
freed (and so requiring this matching thread init/destroy behavior).

0 files changed, 0 insertions, 0 deletions