[PR24444] speed up locview resolution wiht relaxable frags

[Alan Modra]

On Tue, Apr 30, 2019 at 02:49:38AM -0300, Alexandre Oliva wrote:
> AFAICT fixing this will require introducing artificial undefined symbols
> to be used as previous view label and previous view number for each
> subsection, and then, when ordering subsections and sections, defining
> the initial previous symbols of each subsection as equal to the final
> previous symbols of the previous subsection in the same section.

Don't you already keep struct line_entry on per-subseg lists?  Frags
too are kept on per-subseg lists until chain_frchains_together.

-- 
Alan Modra
Australia Development Lab, IBM