buildbot users try branch builders

[Mark Wielaard]

Hi,

As an experiment we now have try builders for binutils and gdb. If you
have commit access to binutils-gdb.git you can now push to your
users/<name>/try-xxx branch and the buildbot will do builds and sent
you (the commit author) email about the results. The builds are also
visible at:

https://builder.sourceware.org/buildbot/#/builders?tags=binutils-try
https://builder.sourceware.org/buildbot/#/builders?tags=gdb-try

My workflow to use this looks like:
- git checkout -b frob
- hack, hack, hack... OK, looks good to submit
- git commit -a -m "Awesome hack"
- git push origin frob:users/mark/try-frob
- ... wait for the emails to come in or watch buildbot logs ...
- Send in patches and mention what the try bot reported

After your patches have been accepted you can delete the branch again:
- git push origin :users/mark/try-frob

Please use this only for patches you intend to submit and think are
ready but want to double check. Use the GCC Compile Farm machines if
you need to hack edit/compile/debug on a specific architecture. But if
you really need access to one of the buildbot machines for
investigating an issue, please contact buildbot@sourceware.org.

The armhf and arm64 builders have left out for now since they are a
bit too slow. We'll hopefully get a 8 core Ampare machine from the
Oregon State University this week so we can also enable those arm
builders.

Tom, I haven't hooked up the debian-ppc64 builder yet. It would take
another ~3GB disk space for the new try builders.

Frank, the try builders also upload logs to the bunsendb. And so are
visible here https://builder.sourceware.org/testruns/
I think this is useful, but maybe these try logs are just noise?

Please sent feedback (bad or good) to buildbot@sourceware.org

Currently this is only for the binutils and gdb projects, but if this
looks useful and when we get some new hardware we can roll it out to
other sourceware projects.

Cheers,

Mark