…chenkov

Stabilize checking of cfgs at compile-time: `--check-cfg` option

This PR stabilize the `--check-cfg` CLI option of `rustc` (and `rustdoc`) 🎉.

In particular this PR does two things:
  1. it makes the `--check-cfg` option stable
  2. and it moves the documentation to the stable books

FCP: rust-lang#82450 (comment)

Resolves rust-lang#82450

`@rustbot` labels  S-blocked  F-check-cfg
r? `@petrochenkov`

…iaskrgr

Rollup of 10 pull requests

Successful merges:

 - rust-lang#122632 (fetch submodule before checking llvm stamp)
 - rust-lang#123355 (Support type '/' to search)
 - rust-lang#123501 (Stabilize checking of cfgs at compile-time: `--check-cfg` option)
 - rust-lang#123535 (Match ergonomics 2024: `mut` doesn't reset binding mode)
 - rust-lang#123711 (drop `changelog-seen`)
 - rust-lang#123969 (The new solver ignores `DefineOpaqueTypes`, so switch it to `Yes`)
 - rust-lang#124007 (Miri subtree update)
 - rust-lang#124017 (Change a diagnostics-path-only `DefineOpaqueTypes` to `Yes`.)
 - rust-lang#124018 (interpret: pass MemoryKind to before_memory_deallocation)
 - rust-lang#124024 (interpret: remove outdated comment)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#123501 - Urgau:stabilize-check-cfg, r=petrochenkov

Stabilize checking of cfgs at compile-time: `--check-cfg` option

This PR stabilize the `--check-cfg` CLI option of `rustc` (and `rustdoc`) 🎉.

In particular this PR does two things:
  1. it makes the `--check-cfg` option stable
  2. and it moves the documentation to the stable books

FCP: rust-lang#82450 (comment)

Resolves rust-lang#82450

``@rustbot`` labels  S-blocked  F-check-cfg
r? ``@petrochenkov``

rust-lang/rust#123501

rust-lang/rust#123501

rust-lang/rust#123501

rust-lang/rust#123501

Stabilize `-Zcheck-cfg` as always enabled

This PR stabilize the `-Zcheck-cfg` option as always enabled.

~~Waiting on rust-lang/rust#82450 (comment) to complete, but is otherwise ready to be reviewed (in particular the documentation changes).~~ (rust-lang/rust#123501)

Fixes #10554

1. allow unexpected cfgs in lib.rs, in this case
   "no_global_oom_handling" is cause warnings [1]

2. for large code models the compiler (rust linkers) now put code and
   data in `.ltext`, `.ldata`, `.lbss`, `.lrodata` instead of the
   same `.text` , `.data` ... etc. We are adjusting accordingly in the
   linker script.

3. unsafe assertions identified undefined behaviours, in this case a repr(C)
   struct was not mared as repr(packed), therefore having an unexpected
   size. The unsafe assertions was not enabled by default in debug
   builds so the idt setup code with from_raw_parts_mut() has been
   working on UB. Glad we can catch this....

related: [1] rust-lang/rust#123501
related: [2] https://blog.rust-lang.org/2024/05/02/Rust-1.78.0.html#asserting-unsafe-preconditions

1. allow unexpected cfgs in lib.rs, in this case
   "no_global_oom_handling" is cause warnings [1]

2. for large code models the compiler (rust linkers) now put code and
   data in `.ltext`, `.ldata`, `.lbss`, `.lrodata` instead of the
   same `.text` , `.data` ... etc. We are adjusting accordingly in the
   linker script.

3. unsafe assertions identified undefined behaviours, in this case a repr(C)
   struct was not mared as repr(packed), therefore having an unexpected
   size. The unsafe assertions was not enabled by default in debug
   builds so the idt setup code with from_raw_parts_mut() has been
   working on UB. Glad we can catch this....

related: [1] rust-lang/rust#123501
related: [2] https://blog.rust-lang.org/2024/05/02/Rust-1.78.0.html#asserting-unsafe-preconditions