Backporting gcc_qsort

[Jeff Law]

On 10/1/18 2:20 AM, Richard Biener wrote:
> On Fri, Sep 28, 2018 at 7:08 PM Cory Fields <lists@coryfields.com> wrote:
>>
>> gcc_qsort as introduced by Alexander Monakov [0] in trunk for 9.x is a
>> great change that defines the order of otherwise-unbalanced internal
>> sorts, some of which would otherwise cause bootstrapping failures.
>>
>> I would like to request that these it as well as subsequent fixups
>> (all listed specifically below) be backported to the 8.x branch. They
>> apply cleanly to 8.x, and I can confirm that they fix qsort-related
>> bootstrap failures at least in my case of crossing x86_64-gnu to
>> x86_64-musl.
>>
>> Would there be any downside to backporting?
> 
> It is not something we generally backport.
To add a bit more context for Cory.

Generally backports are limited to fixing regressions and serious code
generation bugs.  While we do make some exceptions, those are good
general guidelines.

I don't think the qsort changes warrant an exception.

jeff