Add sys/personality.h constants for Linux

[nbaksalyar]

These consts are used for the personality(2) syscall and can be found in /usr/include/sys/personality.h

[rust-highfive]

r? @JohnTitor

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[JohnTitor]

It seems musl and emscripten don't have UNAME26 and FDPIC_FUNCPTRS.

https://github.com/bminor/musl/blob/b4b1e10364c8737a632be61582e05a8d3acf5690/include/sys/personality.h#L8-L16

https://github.com/emscripten-core/emscripten/blob/2bca083cbbd5a4133db61fbd74d04f7feecfa907/system/include/libc/sys/personality.h#L8-L16

You can move them to the platforms that you want to use.

[nbaksalyar]

You can move them to the platforms that you want to use.

Thanks! Will do

[nbaksalyar]

Hmm. CI fails at the StyleAndDocs step with the following error:

+ cargo doc --target aarch64-unknown-cloudabi --no-default-features --features extra_traits
   Compiling libc v0.2.74 (/home/vsts/work/1/s)
 Documenting libc v0.2.74 (/home/vsts/work/1/s)
error[E0463]: can't find crate for `core`
  |
  = note: the `aarch64-unknown-cloudabi` target may not be installed

Any ideas why this might happen?

[JohnTitor]

The problem here is that rust-src for that target is missing in today's nightly. I'll fix it soon, one sec.

[JohnTitor]

Well, I noticed today's nightly is missing rust-src for a lot of targets, testing in #1850, it's... painful :/ Could you wait for fixing this issue on upstream?

[nbaksalyar]

Sure, thanks for your help!

[JohnTitor]

So, it turned out the cargo failure, not component's. I missed this...:

+ cargo doc --target aarch64-unknown-cloudabi -Z build-std=core,alloc --no-default-features --features extra_traits
error: failed to read `/usr/share/rust/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libstd/Cargo.toml`

Caused by:
  No such file or directory (os error 2)

This should be fixed by rust-lang/cargo#8558 and I confirmed the things work well in today's nightly.
Let's re-trigger CI to make it green.

[JohnTitor]

Now it's green, thanks!

[nbaksalyar]

Awesome, thanks :)