setup 2.906 release candidate - please test

[Jon Turney]

On 17/03/2021 20:02, Jon Turney wrote:
> 
> A new setup release candidate is available at:
> 
>    https://cygwin.com/setup/setup-2.906.x86_64.exe (64 bit version)
>    https://cygwin.com/setup/setup-2.906.x86.exe    (32 bit version)
> 
> Please test, and report any problems here.
> 
> This is not the place for setup feature requests.

Pretty late in preparing this release, I discovered that in Fedora 33, 
the MinGW-w64 32-bit compiler has been changed from sjlj to dwarf2 
unwinding C++ exception handling.

I believe this means that exceptions cannot propagate up through Windows 
code, so the release needs to be delayed until the source code has been 
inspected to see if there's any place where e.g. we throw an exception 
from a Windows callback, but I'd like to get this out for some testing 
already.