[rfa] Assume thread-db loaded over a live process

[Andrew Cagney]

> Andrew Cagney wrote:
> 
>> Hello,
>>
>> This patch changes:
>>
>> -      /* We can only poke around if there actually is a child process.
>> -         If there is no child process alive, postpone the steps below
>> -         until one has been created.  */
>> -      if (proc_handle.pid != 0)
>> -       {
>> -         enable_thread_event_reporting ();
>> -         thread_db_find_new_threads ();
>> -       }
>> +      enable_thread_event_reporting ();
>> +      thread_db_find_new_threads ();
>>
>> this code is only executed when there is a child process so the guard isn't needed.    Tested on GNU/Linux, no change in test results.
>>
>> ok?
> 
> 
> From memory, I think this code was to guard against the corefile case.
> When you load a corefile, you may call thread_db_new_objfile, but
> you won't have a child process.  Is that no longer the case?  Does
> loading a corefile no longer cause this function to be called?

This code is only executed when there is a child process.  As you note, 
when loading a core file there is no child process (and as daniel 
pointed out, !target_has_execution holds) so this code is not executed.

Andrew