…ize 24 -> 6 bytes

…nk to installation instructions.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

Specifically, ISO/IEC 9899:2018 — better known as "C18" — (and at least
C11, C99 and C89) do not specify the size of `byte` in bits.
Section 3.6 defines "byte" as "addressable unit of data storage" while
section 6.2.5 ("Types") only defines "char" as "large enough to store
any member of the basic execution set" giving it a lower bound of 7 bit
(since there are 96 characters in the basic execution set).
With section 6.5.3.4 paragraph 4 "When sizeof is applied to an operant
that has type char […] the result is 1" you could read this as the size
of `char` in bits being defined as exactly the same as the number of
bits in a byte but it's also valid to read that as an exception.

In general implementations take `char` as the smallest unit of
addressable memory, which for modern byte-addressed architectures is
overwhelmingly 8 bits to the point of this convention being completely
cemented into just about all of our software.

So is any of this actually relevant at all? I hope not. I sincerely hope
that this never, ever comes up.
But if for some reason a poor rustacean is having to interface with C
code running on a Cray X1 that in 2003 is still doing word-addressed
memory with 64-bit words and they trust the docs here blindly it will
blow up in her face. And I'll be truly sorry for her to have to deal
with … all of that.

Using it through the crate-local path in `std` means that it shouldn't make an "Implementations on Foreign Types" section in the `std::error::Error` docs.

Print a note if a character literal contains a variation selector

Fixes rust-lang#88684.

core::ascii::escape_default: reduce struct size

Cleanup: Remove needless reference in ParentHirIterator

It forces an intermediate binding of `Map` which is a Copy type.

…le, r=kennytm

Stabilize `Iterator::map_while`

Per the FCP: rust-lang#68537 (comment)

This PR stabilizes `Iterator::map_while` and `iter::MapWhile` in Rust 1.57.

…r=jyn514

[bootstrap] Improve the error message when `ninja` is not found to link to installation instructions

fixes rust-lang#89091

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

dont `.ensure()` the `thir_abstract_const` query call in `mir_build`

might fix an ICE seen in rust-lang#89022 (note: this PR does not close that issue) about attempting to read stolen thir. I couldn't repro the ICE but this `.ensure` seems sus anyway.

r? `@lcnr`

Fixes a technicality regarding the size of C's `char` type

Specifically, ISO/IEC 9899:2018 — better known as "C18" — (and at least
C11, C99 and C89) do not specify the size of `byte` in bits.
Section 3.6 defines "byte" as "addressable unit of data storage" while
section 6.2.5 ("Types") only defines "char" as "large enough to store
any member of the basic execution set" giving it a lower bound of 7 bit
(since there are 96 characters in the basic execution set).
With section 6.5.3.4 paragraph 4 "When sizeof is applied to an operant
that has type char […] the result is 1" you could read this as the size
of `char` in bits being defined as exactly the same as the number of
bits in a byte but it's also valid to read that as an exception.

In general implementations take `char` as the smallest unit of
addressable memory, which for modern byte-addressed architectures is
overwhelmingly 8 bits to the point of this convention being completely
cemented into just about all of our software.

So is any of this actually relevant at all? I hope not. I sincerely hope
that this never, ever comes up.
But if for some reason a poor rustacean is having to interface with C
code running on a Cray X1 that in 2003 is still doing word-addressed
memory with 64-bit chars and they trust the docs here blindly it will
blow up in her face. And I'll be truly sorry for her to have to deal
with … all of that.

…=Mark-Simulacrum

⬆️ rust-analyzer

`@bors` r+ rollup

…nkov

Fix ICE when `indirect_structural_match` is allowed

Fixes rust-lang#89088. The ICE is caused by `delay_good_path_bug()`, which is called (indirectly) from a `format!()` macro invocation. I have moved the macro invocation into the `decorate` closure of `struct_span_lint_hir()`, so that the macro is only invoked if the lint is not allowed (i.e., causes at least a warning, and thus prevents `delay_good_path_bug()` from firing).

Impl `Error` for `FromSecsError` without foreign type

Using it through the crate-local path in `std` means that it shouldn't make an "Implementations on Foreign Types" section in the `std::error::Error` docs.

Fix match for placeholder region

cc rust-lang#89118

…q, r=oli-obk

add case for checking const refs in check_const_value_eq

Previously in `check_const_value_eq` we destructured `ConstValue::ByRef` instances, this didn't account for `ty::Ref`s however, which led to an ICE.

Fixes rust-lang#88876
Fixes rust-lang#88384

r? `@oli-obk`