Undocumented: Identifier `r#move` cannot be used as the name of a constant

[wuwbobo2021]

Location

https://doc.rust-lang.org/reference/items/constant-items.html

Summary

//const r#move : i32 = 17760257; // It does not compile
fn main() {
    fn r#move() {} // It does compile
}

   Compiling playground v0.0.1 (/playground)
error: expected item, found keyword `const`
 --> src/main.rs:1:1
  |
1 | const r#move : i32 = 17760257;
  | ^^^^^ expected item
  |
  = note: for a full list of items that can appear in modules, see <https://doc.rust-lang.org/reference/items.html>

error: could not compile `playground` (bin "playground") due to 1 previous error

This may cause problem in generated bindings for APIs in other languages.

https://developer.android.com/reference/android/R.transition.html#move

[cyrgani]

This code used to compile fine in 1.68: https://godbolt.org/z/Mzx6PdTeM, but became a parse error in 1.69. I can't find anything in the release notes about this either.
@rustbot label: regression-from-stable-to-stable S-has-bisection

bisection gives:

---

Regression in nightly-2023-02-06

---

fetching https://static.rust-lang.org/dist/2023-02-05/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2023-02-05: 40 B / 40 B [===================================================================================================] 100.00 % 422.10 KB/s converted 2023-02-05 to 50d3ba5
fetching https://static.rust-lang.org/dist/2023-02-06/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2023-02-06: 40 B / 40 B [===================================================================================================] 100.00 % 424.34 KB/s converted 2023-02-06 to 75a0be9
looking for regression commit between 2023-02-05 and 2023-02-06
fetching (via remote github) commits from max(50d3ba5, 2023-02-03) to 75a0be9
ending github query because we found starting sha: 50d3ba5
get_commits_between returning commits, len: 6
commit[0] 2023-02-04: Auto merge of #107672 - matthiaskrgr:rollup-7e6dbuk, r=matthiaskrgr
commit[1] 2023-02-05: Auto merge of #107434 - BoxyUwU:nll_const_equate, r=compiler-errors
commit[2] 2023-02-05: Auto merge of #107679 - est31:less_import_overhead, r=compiler-errors
commit[3] 2023-02-05: Auto merge of #102842 - rol1510:issue-85566-fix, r=notriddle
commit[4] 2023-02-05: Auto merge of #107663 - matthiaskrgr:107423-point-at-EOF-code, r=compiler-errors
commit[5] 2023-02-05: Auto merge of #107526 - obeis:for-missing-iterator, r=estebank,compiler-errors

[Noratrieb]

The bisection above does not seem to be correct 🤔

This happens because when parsing items, for some reason it checks that it's not a parsing a const closure, and const closures may be const move, and therefore it bails and treats it as invalid.

rust/compiler/rustc_parse/src/parser/mod.rs

Line 757 in 23032f3

token::Ident(kw::Move | kw::Static, _) | token::OrOr | token::BinOp(token::Or) => {