Freeze for 2.42: Desirables, bug fixes, machine testing

[Claudiu Zissulescu-Ianculescu]

> 
>>>    - Add SFrame support for stack backtracing
>>
>> I think it is too late for SFrame, I raised some points in the last iteration
>> and it requires at least a new version to address some comments (specially
>> w.r.t testing). So I think we should postpone it to 2.43 as well (I cc
>> Claudiu).
> 
> I see the many comments. Makes sense but let's wait for Claudiu.
> Can this patchset be backported?
> 

I have sent a new series, most of the patches are already reviewed and
approved by DJ. The only thing left is the new patch in the series which
executes the tst-backtrace* tests using dw unwinder when SFrame is enabled.

Many thanks,
Claudiu