Replace "rc"/"arc" lang items with Rc/Arc diagnostic items.
`Rc`/`Arc` should have no special semantics, so it seems appropriate for them to not be lang items.
r? @matthewjasper
Support `#[track_caller]` on functions in `extern "Rust" { ... }`
Fixes https://github.com/rust-lang/rust/issues/70830 which is the follow-up to @eddyb's suggestion in https://github.com/rust-lang/rust/pull/69251#discussion_r380791634 to allow `#[track_caller]` on `fn`s in FFI imports, that is, on functions in `extern "Rust" { ... }` blocks.
This requires that the other side, the FFI export, also have the `#[track_caller]` attribute. Otherwise, undefined behavior is triggered and the blame lies, as usual, with the `unsafe { ... }` block which called the FFI imported function.
After this PR, all forms of `fn` items with the right ABI (`"Rust"`) support `#[track_caller]`.
As a drive-by, the PR also hardens the check rejecting `#[naked] #[track_caller]` such that methods and other forms of `fn` items are also considered.
r? @eddyb
cc @rust-lang/lang
infer array len from pattern
closes#70529
This still errors in the following case
```rust
#![feature(const_generics)]
fn arr<const N: usize>() -> [u8; N] {
todo!()
}
fn main() {
match arr() {
[5, ..] => (),
//~^ ERROR cannot pattern-match on an array without a fixed length
[_, _] => (),
}
}
```
Considering that this should be rare and is harder to implement I would merge this PR without *fixing* the above.
Add long error code for error E0226
Added a long description message for error E0226, which previously did not exist.
As requested in issue #61137
r? @GuillaumeGomez
Rename asm! to llvm_asm!
As per https://github.com/rust-lang/rfcs/pull/2843, this PR renames `asm!` to `llvm_asm!`. It also renames the compiler's internal `InlineAsm` data structures to `LlvmInlineAsm` in preparation for the new `asm!` functionality specified in https://github.com/rust-lang/rfcs/pull/2850.
This PR doesn't actually deprecate `asm!` yet, it just makes it redirect to `llvm_asm!`. This is necessary because we first need to update the submodules (in particular stdarch) to use `llvm_asm!`.
