julia

f68b102e - gc-stacks: skip the NULL root task of an exited adopted thread (#63630)

gc-stacks: skip the NULL root task of an exited adopted thread (#63630) When an adopted thread exits, `jl_delete_thread` clears its `root_task` but leaves its ptls in `jl_all_tls_states`. `jl_get_all_tasks_arraylist` and `jl_live_tasks` dereferenced `root_task` unconditionally, so the wall-time profiler (and `jl_live_tasks`) segfaulted in any process that had previously adopted a thread that later exited. GC marking and the task backtrace printer already handle the NULL case.