Fixes rust-lang#56503.

RFC rust-lang#2195 specifies that a repr(int) enum such as:

    #[repr(u8)]
    enum MyEnum {
        B { x: u8, y: i16, z: u8 },
    }

has a layout that is equivalent to:

    #[repr(C)]
    enum MyEnumVariantB { tag: u8, x: u8, y: i16, z: u8 },

However this isn't actually implemented, with the actual layout being
roughly equivalent to:

    union MyEnumPayload {
        B { x: u8, y: i16, z: u8 },
    }

    #[repr(packed)]
    struct MyEnum {
        tag: u8,
        payload: MyEnumPayload,
    }

Thus the variant payload is *not* subject to repr(C) ordering rules, and
gets re-ordered as `{ x: u8, z: u8, z: i16 }`

The existing tests added in pull-req rust-lang#45688 fail to catch this as the
repr(C) ordering just happens to match the current Rust ordering in this
case; adding a third field reveals the problem.

This commit updates from LLVM 7.0.0 to git revisions of clang/llvm/lld
to build LLVM on our dist builders for Linux. The goal of this is to
fix rust-lang#56849 by picking up a fix [1] in LLD.

Closes rust-lang#56849

[1]: llvm-mirror/lld@3be4e82

Layout size overflow and typeck eval errors are reported. Trigger a bug
only when the eval error is strictly labeled as TooGeneric.

logic is written up in rust-lang#49048

Also, update the documentation slightly

Remove pin::Unpin reexport and add Unpin to the prelude.
Change Pin associated functions to methods.
Rename get_mut_unchecked_ to get_unchecked_mut
Remove impl Unpin for Pin
Mark Pin repr(transparent)

…the values

…r=Manishearth

Mem uninit doc ptr drop

Extend the mem::uninitialized documentation to account for partially initialized arrays and how to correctly handle these. These are used in some datastructures (trees for example) or in FFI.

r? @Manishearth

make basic CTFE tracing available on release builds

Debugging things going wrong in miri is currently pretty much impossible with a nightly Rust.

r? @oli-obk

…nd-support, r=alexcrichton

Adding unwinding support for x86_64_fortanix_unknown_sgx target.

Unwinding support is provided by our port of LLVM's libunwind which is available from https://github.com/fortanix/libunwind/tree/release_50.

libunwind requires support for rwlock and printing to stderr, which is only provided by `std` for this target. This poses two problems: 1) how to expose the `std` functionality to C and 2) dependency inversion.

### Exposing `std`

For exposing the functionality we chose to expose the following symbols:

* __rust_rwlock_rdlock
* __rust_rwlock_wrlock
* __rust_rwlock_unlock
* __rust_print_err
* __rust_abort

Also, the following are needed from `alloc`:

* __rust_alloc
* __rust_dealloc

#### Rust RWLock in C

In `libunwind`, RWLock is initialized as a templated static variable:

```c
pthread_rwlock_t DwarfFDECache<A>::_lock = PTHREAD_RWLOCK_INITIALIZER;
```

I don't know of a good way to use the Rust sys::rwlock::RWLock type and initializer there. We could have a static global variable in Rust, but that doesn't work with the templating. The variable needs to be initialized statically, since this target doesn't support the .init section. Currently, I just used a byte array and standard C array initialization. The mapping between this C type and the Rust type needs to be manually maintained. There is a compile-time check and a unit test to make sure the Rust versions of these C definitions match the actual Rust type. If any reviewer knows of a better solution, please do tell.

### Dependency inversion issue

`std` depends on `panic_unwind` which depends on `libunwind`, and `libunwind` depends on `std`. This is not normally supported by Rust's linking system. Therefore we use raw C exports from `std` *and* `libunwind.a` is linked last in the target `post_link_objects` instead of being built as part of the Rust `libunwind`. Currently, all C exports are defined in `src/libstd/sys/sgx/rwlock.rs` to overcome LTO issues. Only the `__rust_rwlock_*` definitions *need* to live there for privacy reasons. Once again, if any reviewer knows of a better solution, please do tell.

r? @alexcrichton

…li-obk

miri: allocation is infallible

…i-obk

A few tweaks to dropck_outlives

- remove an unnecessary call to `cloned()`
- simplify common patterns

…ations, r=Mark-Simulacrum

Fix compiletest `trim` deprecation warnings

None

…li-obk

suggest similar lint names for unknown lints

Fixes rust-lang#54737.

AST/HIR: Introduce `ExprKind::Err` for better error recovery in the front-end

This way we can avoid aborting compilation if expansion produces errors and generate `ExprKind::Err`s instead.

…kruppe

Stabilize Vec(Deque)::resize_with

Closes rust-lang#41758

…=GuillaumeGomez

rustdoc: add new CLI flag to load static files from a different location

This PR adds a new CLI flag to rustdoc, `--static-root-path`, which controls how rustdoc links pages to the CSS/JS/font static files bundled with the output. By default, these files are linked with a series of `../` which is calculated per-page to link it to the documentation root - i.e. a relative link to the directory given by `-o`. This is causing problems for docs.rs, because even though docs.rs has saved one copy of these files and is dispatching them dynamically, browsers have no way of knowing that these are the same files and can cache them. This can allow it to link these files as, for example, `/rustdoc.css` instead of `../../rustdoc.css`, creating a single location that the files are loaded from.

I made sure to only change links for the *static* files, those that don't change between crates. Files like the search index, aliases, the source files listing, etc, are still linked with relative links.

r? @GuillaumeGomez

cc @onur

Enable emission of alignment attrs for pointer params

Instead disable creation of assumptions during inlining using an LLVM opt flag. For non-inlined functions, this gives us alignment information, while not inserting any assumes that kill other optimizations.

The `-Z arg-align-attributes` option which previously controlled this behavior is removed.

Fixes rust-lang#54982.

r? @nagisa

cc @eddyb who added the current behavior, and @scottmcm, who added the `-Z arg-align-attributes` flag.

Optimize away a move

r? @michaelwoerister

Remove QueryResult

r? @michaelwoerister

…r=Centril

fix deprecation warnings in liballoc benches

Inline tweaks

r? @michaelwoerister

…eature-gate, r=Centril

Fix feature gate to point to 1.32.0 for `path_from_str`

When the feature has been added back (rust-lang#55148) the feature gate has not
been adjusted accordingly. We have it enabled for 1.32.0, currently in
Beta, so adjust it.

Refs: rust-lang#44431.

Signed-off-by: Otavio Salvador <[email protected]>

Stabilize #[repr(packed(N))]

Fixes rust-lang#33158

Fixed typo in HashMap documentation

Previously "with a custom type as key", now "with a custom key type"

…arkor

Fix stabilization version numbers (exhaustive_integer_patterns + macro_literal_matcher)

+ `exhaustive_integer_patterns` slipped 1.32; merged in 1.33 -- rust-lang#56362
+ `macro_literal_matcher` isn't stable on current stable (1.31) but is on beta (1.32).

r? @varkor

Fix alignment for array indexing

We need to reduce the alignment with the used offset. If the offset isn't known, use the element size, as this will yield the minimum possible alignment.

This handles both direct array indexing, and array repeat expressions.

Fixes rust-lang#56927.

r? @nagisa