Adding XCore buildbot and fixing failing tests

Some LLVM and Clang tests fail when XCore is the only or default target.

The failures at one point a few years ago were reported in

The current number is about 170. Many of these are due to XCore not supporting object emission and using an external assembler. Others require tweaks to the test. No Clang/LLVM code changes are required (based on our last rebase).

These upstream failures have been missed because we have not had a buildbot for XCore as the default target, and the shipping compiler diverged from upstream.

We plan to add an XCore buildbot, fix the failures, and make upstream the live compiler.

We thought it would be best to add the new buildbot worker to the staging (silent) buildbot master. This will show the existing failures, without emailing out on every commit. Submitting our fixes will reduce the failures until the builder goes green. Then it could be attached to the main buildmaster, to report regressions on future commits.

Does that sound reasonable?



Sounds good to me