Performance issues with -ffunction-sections and dwarf2 debug line info

[Nicolas Roche]

Alan Modra wrote:
>
> Thanks for the analysis and patch.  It looks OK to me as all places that
> traverse the list don't care too much about the order.  I'm going to
> apply the following slightly different patch instead, so we don't need
> another static var and to make line_seg and line_subseg list addition
> look similar.

Thanks for your review (I just see that I forgot to provide a Changelog 
entry ... will do next time).

Just a little question. Will you apply that patch on the 2.17 branch as 
well so that this fix is included in the upcoming 2.17 release ?

Nicolas Roche