When CI rustc is enabled, bootstrap tries to symlink the rust source (project root)
into target sysroot right before copying it from the CI rustc's sysroot. This becomes
a problem in CI builders (which we currently don't see because they don't use CI rustc)
because the copying part will fail as they run on read-only mode.

This change fixes the problem by copying `rustc-src` from the CI rustc sysroot and only symlinking
`rustc-src` from the rust source when download-rustc is not enabled.

Signed-off-by: onur-ozkan <[email protected]>

Signed-off-by: onur-ozkan <[email protected]>

…path

…-ou-se

Stabilize `PanicInfo::message()` and `PanicMessage`

Resolves rust-lang#66745

This stabilizes the [`PanicInfo::message()`](https://doc.rust-lang.org/nightly/core/panic/struct.PanicInfo.html#method.message) and [`PanicMessage`](https://doc.rust-lang.org/nightly/core/panic/struct.PanicMessage.html).

Demonstration of [custom panic handler](https://github.com/StackOverflowExcept1on/panicker):
```rust
#![no_std]
#![no_main]

extern crate libc;

#[no_mangle]
extern "C" fn main() -> libc::c_int {
    panic!("I just panic every time");
}

#[panic_handler]
fn my_panic(panic_info: &core::panic::PanicInfo) -> ! {
    use arrayvec::ArrayString;
    use core::fmt::Write;

    let message = panic_info.message();
    let location = panic_info.location().unwrap();

    let mut debug_msg = ArrayString::<1024>::new();
    let _ = write!(&mut debug_msg, "panicked with '{message}' at '{location}'");

    if debug_msg.try_push_str("\0").is_ok() {
        unsafe {
            libc::puts(debug_msg.as_ptr() as *const _);
        }
    }

    unsafe { libc::exit(libc::EXIT_FAILURE) }
}
```
```
$ cargo  stage1 run --release
panicked with 'I just panic every time' at 'src/main.rs:8:5'
```

- [x] FCP: rust-lang#66745 (comment)

r? libs-api

…=joshtriplett,calebcartwright

Add nightly style guide section for `precise_capturing` `use<>` syntax

r? style

Tracking:

- rust-lang#123432

linker: Refactor interface for passing arguments to linker

Separate arguments into passed to the underlying linker, to cc wrapper, or supported by both.
Also avoid allocations in all the argument passing functions.

The interfaces would look nicer if not the limitations on returning `&mut Self` in `dyn`-compatible traits, and unnecessary conflicts between `Trait` and `dyn Trait` methods.

try-job: armhf-gnu
try-job: aarch64-gnu
try-job: dist-x86_64-linux
try-job: x86_64-msvc
try-job: i686-msvc
try-job: dist-x86_64-apple
try-job: test-various

Migrate `volatile-intrinsics`, `weird-output-filenames`, `wasm-override-linker`, `wasm-exceptions-nostd` to `rmake`

Also refactors `wasm-abi` and `compressed-debuginfo`.

Part of rust-lang#121876.

r? ``@jieyouxu``

try-job: x86_64-gnu-debug
try-job: dist-various-2

…tion_abs_diff, r=joboet

Stabilize `duration_abs_diff`

Stabilize `duration_abs_diff` following FCP in rust-lang#117618. Closes rust-lang#117618.

…jieyouxu

Use full expr span for return suggestion on type error/ambiguity

We sometimes use parts of an expression rather than the whole thing for an obligation span. For example, a method obligation will just point to the path segment corresponding to the `method` in `rcvr.method(args)`.

So let's not use that assuming it'll point to the *whole* expression span, which we can access from the expr hir id we store in `ObligationCauseCode::WhereClauseInExpr`.

Fixes rust-lang#127109

 improve the way bootstrap handles rustlib components

When CI rustc is enabled, bootstrap tries to symlink the rust source (project root) into target sysroot right before copying it from the CI rustc's sysroot. This becomes a problem in CI builders (which we currently don't see because they don't use CI rustc) because the copying part will fail as [they run on read-only mode](https://github.com/rust-lang/rust/blob/ef3d6fd7002500af0a985f70d3ac5152623c1396/src/ci/docker/run.sh#L233).

This change fixes the problem by copying `rustc-src` from the CI rustc sysroot and only symlinking `rustc-src` from the rust source when download-rustc is not enabled.

r? ``@Kobzol`` (we talked about this already on Zulip, he knows the context)

Blocker for rust-lang#122709

…pport, r=Kobzol

Improve run-make-support API

I think I'll slowly continue this work. Makes things a bit nicer for contributors, so why not. :D

r? ``@Kobzol``