Automatic Rustup

Automatic Rustup

Fixes rust-lang#3595 by using -fvisibility=hidden and the visibility attribute supported by both gcc and clang rather than the previous gcc-only mechanism for symbol hiding. Also brings over cfg changes from rust-lang#3594 which enable native-lib functionality on all unixes.

Enable native libraries on macOS

Fixes rust-lang#3595 by using `-fvisibility=hidden` and the visibility attribute supported by both gcc and clang rather than the previous gcc-only mechanism for symbol hiding. Also brings over cfg changes from rust-lang#3594 which enable native-lib functionality on all unixes.

Thanks for taking a look, feedback very welcome!

cc `@RalfJung`

See: rust-lang#3749

…alfJung

Detect when pthread_mutex_t is moved

What I am not sure about this PR is how to support storing the additional mutex data like its address and kind. If I understand correctly the `concurrency::sync::Mutex` struct is to be used by any mutex implementation. This possibly means that different implementation might want to store different data in the mutex. So any additional data should be implementation defined somehow. Solutions that come to mind:

- Store the additional data as `Box<dyn Any>` and the implementations can downcast their data when they fetch them.
- Have each shim implementation define a `static mut` map between `MutexID`s and the additional data.

Let me know

Fixes rust-lang#3749

Automatic Rustup

miri.bat: use nightly toolchain

Hopefully fixes rust-lang/miri#3863 (but I can't test that)

We no longer store the kind inside the pthread_mutex_t, so this comment
is outdated.

…fJung

Fix comment in mutex_id_offset

We no longer store the kind inside the pthread_mutex_t, so this comment is outdated.
Sorry I didn't catch this in the original PR.