…d doctests

Rewrite these blobs to explicitly mention the case of a sized operand.
The previous made that seem wrong instead of emphasizing it is nothing
but a simple cast. Instead, the explanation now emphasizes that the
address portion of the argument, together with its provenance, is
discarded which previously had to be inferred by the reader. Then an
example demonstrates a simple line of incorrect usage based on this
idea of provenance.

…nt but not valid Unicode

This special case in `output_base_dir` had the unfortunate side-effect of
causing all run-make tests to share the same `stamp` file. So as soon as any
one of them succeeded, all of the failed tests would be considered up-to-date
and would no longer run in subsequent test invocations.

`utcnow()` is deprecated in favor of passing a timezone to `now()`. `utcnow()` would return a tz-naive datetime, while this returns a tz-aware datetime. For the purposes of the formatting we do, these are the same.

Some float methods are now `const fn` under the `const_float_methods` feature gate.

In order to support `min`, `max`, `abs` and `copysign`, the implementation of some intrinsics had to be moved from Miri to rustc_const_eval.

…ror, r=compiler-errors

Fix bug where `option_env!` would return `None` when env var is present but not valid Unicode

Fixes rust-lang#122669 by making `option_env!` emit an error when the value of the environment variable is not valid Unicode.

…alfJung,tgross35

Make some float methods unstable `const fn`

Some float methods are now `const fn` under the `const_float_methods` feature gate.

I also made some unstable methods `const fn`, keeping their constness under their respective feature gate.

In order to support `min`, `max`, `abs` and `copysign`, the implementation of some intrinsics had to be moved from Miri to rustc_const_eval (cc ```@RalfJung).```

Tracking issue: rust-lang#130843

```rust
impl <float> {
    // #[feature(const_float_methods)]
    pub const fn recip(self) -> Self;
    pub const fn to_degrees(self) -> Self;
    pub const fn to_radians(self) -> Self;
    pub const fn max(self, other: Self) -> Self;
    pub const fn min(self, other: Self) -> Self;
    pub const fn clamp(self, min: Self, max: Self) -> Self;
    pub const fn abs(self) -> Self;
    pub const fn signum(self) -> Self;
    pub const fn copysign(self, sign: Self) -> Self;

    // #[feature(float_minimum_maximum)]
    pub const fn maximum(self, other: Self) -> Self;
    pub const fn minimum(self, other: Self) -> Self;

    // Only f16/f128 (f32/f64 already const)
    pub const fn is_sign_positive(self) -> bool;
    pub const fn is_sign_negative(self) -> bool;
    pub const fn next_up(self) -> Self;
    pub const fn next_down(self) -> Self;
}
```

r? libs-api

…workingjubilee

Implemented `FromStr` for `CString` and `TryFrom<CString>` for `String`

The motivation of this change is making it possible to use `CString` in generic methods with `FromStr` and `TryInto<String>` trait bounds. The same traits are already implemented for `OsString` which is an FFI type too.

…bles, r=notriddle

Use environment variables instead of command line arguments for merged doctests

Fixes [rust-lang#130796](rust-lang#130796).

Before merging this one, let's first ensure it has a smaller impact compared to command line arguments (results can be seen [here](rust-lang#130285)). I'll start a crater run once CI passed.

cc `@ehuss`
r? `@notriddle`

Add 1.82 release notes

cc ```@rust-lang/release```

This is using the new release notes infrastructure. My expectation is that most and/or all edits should be made separately from this PR by updating various relnote tracking issues, and then we'll re-run the relnotes tool. That probably comes with an exception for the stabilized APIs for std, which will need to be manually added at the end.

…tation, r=Mark-Simulacrum

Expand set_ptr_value / with_metadata_of docs

In preparation of a potential FCP, intends to clean up and expand the documentation of this operation.

Rewrite these blobs to explicitly mention the case of a sized operand. The previous made that seem wrong instead of emphasizing it is nothing but a simple cast. Instead, the explanation now emphasizes that the address portion of the argument, together with its provenance, is discarded which previously had to be inferred by the reader. Then an example demonstrates a simple line of incorrect usage based on this idea of provenance.

Tracking issue: rust-lang#75091

…age, r=compiler-errors

Update lint message for ABI not supported

Tracking issue: rust-lang#130260

As requested in rust-lang#128784 (review) I updated the error message.

I could also change it to be the same message as if it was a hard error on a normal function:

> "`{abi}` is not a supported ABI for the current target"

Or would that get confusing when people try to google the error message?

r? compiler-errors

…youxu

Fix up-to-date checking for run-make tests

This special case in `output_base_dir` had the unfortunate side-effect of causing all run-make tests to share the same `stamp` file. So as soon as any one of them succeeded, all of the failed tests would be incorrectly considered up-to-date and would no longer run in subsequent test invocations.

Fixes rust-lang#129971.

r? jieyouxu

Resolved python deprecation warning in publish_toolstate.py

`utcnow()` is deprecated in favor of passing a timezone to `now()`. `utcnow()` would return a tz-naive datetime, while this returns a tz-aware datetime. For the purposes of the formatting we do, these are the same.

Fix two const-hacks

Fix two pieces of code marked `FIXME(const-hack)` related to const_option rust-lang#67441.