ACP: rust-lang/libs-team#156

Signed-off-by: Andrew Wock <[email protected]>

With rust 1.75 the absolute build path is embedding into '.rustc' section and which causes reproducibility issues. Detailed issue is here.
rust-lang#120825 (comment)

With this change the 'absolute path' changed back to '/rust/$hash' format.

Unnamed union fields with enums are checked for, but if `find_field`
causes an ICE then the compiler won't get to that point.

Signed-off-by: David Wood <[email protected]>

…types_defined_by`

Instead, when we're collecting opaques for associated items, we choose the right collection mode depending on whether we're collecting for an associated item of a trait impl or not.

Implement MaybeUninit::fill{,_with,_from}

ACP: rust-lang/libs-team#156

…r=cuviper

std support for wasm32 panic=unwind

Tracking issue: rust-lang#118168

This adds std support for `-Cpanic=unwind` on wasm, and with it slightly more fleshed out rustc support. Now, the stable default is still panic=abort without exception-handling, but if you `-Zbuild-std` with `RUSTFLAGS=-Cpanic=unwind`, you get wasm exception-handling try/catch blocks in the binary:

```rust
#[no_mangle]
pub fn foo_bar(x: bool) -> *mut u8 {
    let s = Box::<str>::from("hello");
    maybe_panic(x);
    Box::into_raw(s).cast()
}

#[inline(never)]
#[no_mangle]
fn maybe_panic(x: bool) {
    if x {
        panic!("AAAAA");
    }
}
```
```wat
;; snip...
(try $label$5
 (do
  (call $maybe_panic
   (local.get $0)
  )
  (br $label$1)
 )
 (catch_all
  (global.set $__stack_pointer
   (local.get $1)
  )
  (call $__rust_dealloc
   (local.get $2)
   (i32.const 5)
   (i32.const 1)
  )
  (rethrow $label$5)
 )
)
;; snip...
```

…li-obk

Hint user to update nightly on ICEs produced from outdated nightly

This is a conservative best-effort approach to detect a potentially outdated nightly; it will fallback to the regular ICE-reporting if any of the following cases are true:
- Channel is not nightly
- Version information is not available
- Version date is not parseable as a YYYY-MM-DD or is missing
- System time is at least 36 hours ahead of the user's nightly release datetime.
- Any internal features are used.

Note that I'm not sure how to make a test for this: I tested this manually by `CFG_VER_DATE="2020-02-02" ./x build library --stage 1`, and also changing the channel detection in `rustc_driver_impl` from `Some("nightly")` to `Some("nightly" | "dev")`, and then running `rustc +stage1 test.rs -Ztreat-err-as-bug=1` with a non-existent `test.rs`.

<img width="1145" alt="Screenshot 2024-02-27 at 01 12 28" src="https://github.com/rust-lang/rust/assets/39484203/eff6af2e-4b19-4a70-af57-cd739ecf0e84">

Closes rust-lang#118832.

Removing absolute path in proc-macro

With rust 1.75 the absolute build path name is embedding into proc-macro (.rustc section) and which causes reproducibility issues.
Detailed issue description is here - rust-lang#120825 (comment)

With this change the 'absolute path' changed back to '/rust/$hash' format as in earlier revisions.

…ochenkov

add test for rust-lang#78894 rust-lang#71450

fixes rust-lang#78894
fixes rust-lang#71450

…nkov

hir_analysis: enums return `None` in `find_field`

Fixes rust-lang#121757.

Unnamed union fields with enums are checked for, but if `find_field` causes an ICE then the compiler won't get to that point.

…th, r=bjorn3

Fix duplicated path in the "not found dylib" error

While working on the gcc backend, I couldn't figure out why I had this error:

```
error: couldn't load codegen backend /checkout/compiler/rustc_codegen_gcc/target/release/librustc_codegen_gcc.so/checkout/compiler/rustc_codegen_gcc/target/release/librustc_codegen_gcc.so: cannot open shared object file: No such file or directory
```

As you can see, the path is duplicated for some reason. After investigating a bit more, I realized that `libloading::Error::LoadLibraryExW` starts with the path of the not found dylib, making it appear twice in our error afterward (because we do render it like this: `{path}{err}`, and since the `err` starts with the path...).

Thanks to ```@bjorn3``` for linking me to rust-lang#121392. :)

…_by_queries, r=compiler-errors

Merge impl_trait_in_assoc_types_defined_by query back into `opaque_types_defined_by`

Instead, when we're collecting opaques for associated items, we choose the right collection mode depending on whether we're collecting for an associated item of a trait impl or not.

r? `@compiler-errors`

follow up to rust-lang#121838

will_wake tests fail on Miri and that is expected

Follow-up to rust-lang#121622
r? `@cuviper` `@dtolnay`

only set noalias on Box with the global allocator

As discovered in rust-lang/miri#3341, `noalias` and custom allocators don't go well together.

rustc can now check whether a Box uses the global allocator. This replaces the previous ad-hoc and rather unprincipled check for a zero-sized allocator.

This is the rustc part of fixing that; Miri will also need a patch.