This is create symmetry between the already existing TAU constant (2pi)
and the newly-introduced FRAC_1_SQRT_2PI, keeping the more common
name while increasing visibility.

When things like our internal hashing or representations change,
it is inappropriate for these tests to suddenly fail for no reason.
The chance of error is reduced if we instead pattern-match.

These are the default package set required by opt-dist to correctly work,
hence for people wanting to build a production grade of rustc in a
sandboxed / air-gapped environment, these need to be vendored.

The size of `rustc-src-nightly.tar.xz` before and after this change:

* Before: 298M
* After: 323M (+8%)

These crates are the default set of packages required by opt-dist
to correctly work, hence for people wanting to build a production grade
of rustc in an sandboxed / air-gapped environment, these need to be vendored.

The size of `rustc-src-nightly.tar.xz` before and after this change:

* Before: 298M
* After: 323M (+8%)

Size change might or might not be a concern.
See the previous discussion: rust-lang#125166 (comment)

Previous efforts on making:

* rust-lang#125125
* rust-lang#125166

---

Note that extra works still need to be done to make it fully vendored.

* The current pinned rustc-perf uses `tempfile::Tempdir` as the working
  directory when collecting profiles from some of these packages.
  This "tmp" working directory usage make it impossible for Cargo to pick
  up the correct vendor sources setting in `.cargo/config.toml` bundled
  in the rustc-src tarball. [^1]
* opt-dist verifies the final built rustc against a subset of rustc test
  suite. However it rolls out its own `config.toml` without setting
  `vendor = true`, and that results in `./vendor/` directory removed.
  [^2]

[^1]: https://github.com/rust-lang/rustc-perf/blob/4f313add609f43e928e98132358e8426ed3969ae/collector/src/compile/benchmark/mod.rs#L164-L173
[^2]: https://github.com/rust-lang/rust/blob/606afbb617a2949a4e35c4b0258ff94c980b9451/src/tools/opt-dist/src/tests.rs#L62-L77

`ring` is included because it is an optional dependency of `hyper`,
which is a training data in rustc-pref for optimized build.
The license of it is generally `ISC AND MIT AND OpenSSL`,
though the `package.license` field is not set.

See briansmith/ring#902

`git+https://github.com/rust-lang/team` git source is from
`rust_team_data`, which is used by `site` in src/tools/rustc-perf.
This doesn't really a part of the compiler,
so doesn't really affect the bootstrapping process.

See rust-lang/rustc-perf#1914.

…=cjgillot

Enable GVN for `AggregateKind::RawPtr`

Looks like I was worried for nothing; this seems like it's much easier than I was originally thinking it would be.
r? `@cjgillot`

This should be useful for `x[..4]`-like things, should those start inlining enough to expose the lengths.

…=Mark-Simulacrum

Add `FRAC_1_SQRT_2PI` constant to f16/f32/f64/f128

This adds the `FRAC_1_SQRT_2PI` to the `f16`, `f32`, `f64` and `f128` as [`1/√(2π)`](https://www.wolframalpha.com/input?i=1%2Fsqrt%282*pi%29). The rationale is that while `FRAC_1_SQRT_PI` already exists, [Gaussian calculations](https://en.wikipedia.org/wiki/Gaussian_function) for random normal distributions require a `1/(σ√(2π))` term, which could then be directly expressed e.g. as `f32::FRAC_1_SQRT_2PI / sigma`.

The actual value is approximately `1/√(2π) = 0.3989422804014326779399460599343818684758586311649346576659258296…`. Truncated/rounded forms were used for the individual types.

---

~~I did not any of the `#[unstable]` attributes since I am not aware of their implications.~~

**Edit:** I applied the stability attributes from the surrounding types according to what seemed most likely correct. I believe the `more_float_constants` feature marker is incorrectly applied, but I wasn't sure how to proceed.

…Simulacrum

bootstrap: vendor crates required by opt-dist to collect profiles

These are the default package set required by opt-dist to correctly work,
hence for people wanting to build a production grade of rustc in a
sandboxed / air-gapped environment, these need to be vendored.

The size of `rustc-src-nightly.tar.xz` before and after this change:

* Before: 298M
* After: 323M (+8%)

Size change might or might not be a concern.
See the previous discussion: rust-lang#125166 (comment)

Previous efforts on making:

* rust-lang#125125
* rust-lang#125166

---

Note that extra works still need to be done to make it fully vendored.

* The current pinned rustc-perf uses `tempfile::Tempdir` as the working
  directory when collecting profiles from some of these packages.
  This "tmp" working directory usage make it impossible for Cargo to pick
  up the correct vendor sources setting in `.cargo/config.toml` bundled
  in the rustc-src tarball. [^1]
* opt-dist verifies the final built rustc against a subset of rustc test
  suite. However it rolls out its own `config.toml` without setting
  `vendor = true`, and that results in `./vendor/` directory removed.
  [^2]

[^1]: https://github.com/rust-lang/rustc-perf/blob/4f313add609f43e928e98132358e8426ed3969ae/collector/src/compile/benchmark/mod.rs#L164-L173
[^2]: https://github.com/rust-lang/rust/blob/606afbb617a2949a4e35c4b0258ff94c980b9451/src/tools/opt-dist/src/tests.rs#L62-L77

…mulacrum

Add release notes for 1.79.0

cc `@rust-lang/release`
r? `@Mark-Simulacrum`

…codegen-tests, r=Mark-Simulacrum

Remove hard-coded hashes from codegen tests

This removes hard-coded hashes from the codegen and assembly tests. These use FileCheck, which supports eliding part of the pattern being matched, including by capturing it as a pattern parameter for later matching-on. This is much more appropriate than asking contributors to engage with deliberately-opaque identifier schemes.

In order to reduce the likelihood of error, every hash-coded segment I've touched now expects a certain length. This correctly represents these cases, as our hash outputs have a predetermined amount of entropy attached to them.

This is not done for the UI test suite as those are comparatively easy to simply `--bless`, whereas that would be inappropriate for codegen tests. It is also not done for debuginfo tests as those tests do not support such elision in a correct and useful way.

…youxu

Fix documentation for `impl_common_helpers` in `run-make-support`

Forgot to do this in rust-lang#126121.

`@bors` rollup

r? `@jieyouxu`