[v3] libstdc++/24469

[Paolo Carlini]

Richard Guenther wrote:

>Sure - I specifically looked at v7 branch because Benjamins patch was for v7,
>especially _not_ v3.  And in v7, _M_thread_id is only set, not read.
>
The issue, 24469 certainly pre-dates the recent performance improvements 
committed in v7-branch only, for the moment. It can well be that v7 is 
now not affected, bugged in different ways, I don't know. I just want to 
make sure we agree about the real matter of the original PR, then we can 
move ahead.

Thanks,
Paolo.