Cherry-pick r295964 and closely related part of r282387

[whitequark]

Fixes rust-lang/rust#41672.

[TimNN]

Is this fix for rust nightly or beta / stable?

If it is for nightly you'll want to use rust-llvm-2017-04-13 as the base branch, in which case I think that r282387 should already be included.

[whitequark]

If it is for nightly you'll want to use rust-llvm-2017-04-13 as the base branch, in which case I think that r282387 should already be included.

But yesterday's nightly crashes as described in rust-lang/rust#41672.

[TimNN]

But yesterday's nightly crashes as described in rust-lang/rust#41672.

Note that my statement only refers to r282387, not r295964.

[whitequark]

Updated.

[alexcrichton]

@whitequark would it be possible to do a literal git cherry-pick? It looks like the commit here was crafted by hand?

[whitequark]

@alexcrichton No. There is about a dozen commits between the root branch and the bugfix, all interdependent, and most with significant changes.

[TimNN]

No. There is about a dozen commits between the root branch and the bugfix, all interdependent, and most with significant changes.

@whitequark: Huh? A git cherry-pick of llvm-mirror/llvm@93418ee causes a minor merge conflict in a test but otherwise applies cleanly for me?

[whitequark]

@TimNN Ahhh hm, not sure what went wrong--I must have mixed up something. If you already have the right branch any chance you could simply push it?

[TimNN]

Sure.

[TimNN]

I've pushed the updated cherry pick.

[whitequark]

Thanks!