Rebase LLVM to 8.0.0 final

[cuviper]

r? @alexcrichton

[rust-highfive]

⚠️Warning⚠️

• These commits modify submodules.

[alexcrichton]

Want to update src/rustllvm/llvm-rebuild-trigger while you're at it?

Feel free to r=me with that in

[cuviper]

Oops, updated! Was this not an issue on prior LLVM updates since then?

@bors r=alexcrichton

[bors]

@cuviper: 🔑 Insufficient privileges: Not in reviewers

[Xanewok]

@bors delegate+ r=alexcrichton

[bors]

📌 Commit 0dabf8c has been approved by alexcrichton

[bors]

✌️ @cuviper can now approve this pull request

[nikic]

What are the plans regarding LLVM updates from this point on? Will we stay on the LLVM 8 branch or go back to master now that the release is out?

[alexcrichton]

@cuviper

Was this not an issue on prior LLVM updates since then?

It's never an issue for CI because we always build from scratch and let sccache cache. It's in theory always an issue for local users though because we don't clear out the cached llvm build directory unless this file changes.

Now that being said it's probably pretty trivial for us to clear out the build directory somewhat automatically if the llvm git commit changes or something like that. But for now it's what we have!

@nikic

What are the plans regarding LLVM updates from this point on? Will we stay on the LLVM 8 branch or go back to master now that the release is out?

I think we'll probably stick to the defacto policy we've had for awhile that for small features and updates we can cherry-pick to our own branch but if a major feature is needed we can upgrade the submodule.

[Centril]

@bors p=1

[bors]

⌛ Testing commit 0dabf8c with merge d615b111ad3f43493f62248ea9adbf1e813a1c54...

[bors]

💔 Test failed - checks-travis

[rust-highfive]

The job dist-x86_64-apple of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[02:52:05] Compiling crc32fast v1.1.2
[02:52:05] [RUSTC-TIMING] memoffset test:false 0.108
[02:52:05] Compiling rayon-core v1.4.0
[02:52:06] Compiling yaml-rust v0.3.5
The job exceeded the maximum time limit for jobs, and has been terminated.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[jseyfried]

@bors retry

[bors]

⌛ Testing commit 0dabf8c with merge dd363d1...

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: alexcrichton
Pushing dd363d1 to master...