[DO NOT MERGE] Upgrade libcompiler-builtins

[ishitatsuyuki]

r? @alexcrichton

The plan is perform a try, get the artifacts and check if the sanitizers work.

[kennytm]

The CI is green? You need to modify .travis.yml to enable the ARM jobs if you want to try those.

[ishitatsuyuki]

No, no. Sanitizers are never tested in CI, so we need an artifact to do so. ARM is unrelated to sanitizers.

[kennytm]

I see.

[ishitatsuyuki]

Can anyone with privilege run a try?

[kennytm]

@ishitatsuyuki The try build won't run any tests. Or do you just want to get a compiler artifact?

[ishitatsuyuki]

Yes, I want an artifact.

[kennytm]

@bors try

[bors]

⌛ Trying commit 5d9f51f with merge d0bb1acac6b8f99d97fc6a43d2d974088012cfe4...

[bors]

☀️ Test successful - status-travis
State: approved= try=True

[alexcrichton]

For others watching, this is related to rust-lang/compiler-builtins#202. I'm still not super comfortable merging an update to compiler-rt without also updating LLVM, AFAIK they're meant to be kept in tandem and it seems like ripe opportunity for subtle bugs if they get out of sync.

[ishitatsuyuki]

@alexcrichton, test results:

ASan in release mode seems partially broken. Invalid memory accesses doesn't trigger an error, but LeakSanitizer does kick in.

ASan in debug mode doesn't compile at all due to #45220. -Ccodegen-units=1 doesn't have an effect.

Maybe LLVM upgrade is needed then. Feel free to close.