cmake: Install CheckAtomic.cmake (needed by lldb)

[vivkong]

Summary:
Install CheckAtomic.cmake along with other LLVM modules, therefore making it possible for other projects to use it. This file is needed for LLDB to be built standalone, and installing it was suggested in https://reviews.llvm.org/D23881.

Patch by: Michał Górny

Reviewers: krytarowski, zturner, eugenis, jyknight, labath, beanz

Subscribers: beanz, llvm-commits

Differential Revision: https://reviews.llvm.org/D23887

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279777 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit fdda55b)

[vivkong]

Any update on this one please?

[tfiala]

LGTM.

[tfiala]

@bob-wilson or @llvm-beanz, I'm not on the merge list for swift-llvm. Can one of you get somebody with merge rights to merge this in? Thanks!

[fredriss]

@swift-ci please test

[fredriss]

@vivkong this PR should be directed to swift-3.1-branch, not stable. The swift-llvm and swift-clang repos don't use the stable branches

[jrose-apple]

That's not quite correct. We use stable for things that aren't going into swift-3.1-branch but are needed to build Swift master. At this point in the release cycle that's probably "nothing", but as we get closer to the end there might be a period before LLVM and Clang rebranch where it'll be necessary.

(The latest release branch is always automerged into "stable" these days, so the commit will end up in both places.)

[fredriss]

@vivkong For some reason you changed the destination and then you reverted it to 'stable'

[vivkong]

@fredriss Sorry! I tried to change the destination but when I did it caused a lot of other commits so I reverted back. I'll change the destination once I have my branch aligned with the swift-3.1-branch.

[vivkong]

@fredriss This PR now targets swift-3.1-branch. Thanks.

[fredriss]

@swift-ci please test

[tfiala]

@vivkong this PR should be directed to swift-3.1-branch, not stable.

Wait no. Our Swift CI builds the swift master and LLDB master branches against llvm/clang stable, and swift master-next and LLDB master-next branches against llvm/clang stable-next branches.

So I would fully expect this change to go into both stable and stable-next.

[tfiala]

(It can also go into the 3.1 branch as well, but it definitely should go in stable and stable-next).

[vivkong]

Just to confirm, should I have 2 PRs? One for stable and one for swift-3.1-branch?

[fredriss]

No, this PR is fine. The change will be forwarded to stable automatically.

[tfiala]

Okay I spoke with Fred and Bob. There is an automerge step from swift-3.1-branch into stable for swift-llvm and swift-clang repos. The correct place to put this is in swift-3.1-branch at this point.

The second place to put this is in swift-llvm/stable-next, which is where the master-next bots build.

[fredriss]

@swift-ci please test

[tfiala]

Looks like some kind of Jenkins failure. Retrying the build...

@swift-ci Please test

[tfiala]

@shahmishal, can you have a look at the CI? The update repo step seems to be failing in a way that is not clear to me.

[shahmishal]

@fredriss @tfiala This failure is due to update-checkout script does not have support for swift-3.1-branch yet.

[fredriss]

@shahmishal Is someone working on fixing this?

[shahmishal]

@fredriss Which branches should the CI checkout for llvm/clang swift-3.1-branch?

Does this look right?

            "repos": {
                "llvm": "swift-3.1-branch",
                "clang": "swift-3.1-branch",
                "swift": "master",
                "lldb": "master",
                "cmark": "master",
                "llbuild": "master",
                "swiftpm": "master",
                "compiler-rt": "swift-3.1-branch",
                "swift-corelibs-xctest": "master",
                "swift-corelibs-foundation": "master",
                "swift-corelibs-libdispatch": "master",
                "swift-integration-tests": "master",
                "swift-xcode-playground-support": "master"
            }

[jrose-apple]

I don't think it's meaningful to check out any of the downstream projects at all at this point. Do we have a mode that only supports testing the three LLVM projects?

[jrose-apple]

On the other hand, since changes do get merged into stable, I guess we will be building Swift master against it pretty soon. We just have to remember to update it later.

[fredriss]

@shahmishal sorry I missed you message, yes this setup looks fine.

[fredriss]

@swift-ci please test

[fredriss]

@vivkong Sorry for the delay, this fell through the cracks. The CI is correctly setup now and passes. I'm merging this

[vivkong]

Thanks @fredriss!