const prop missing diagnostic with unrelated changes

[oli-obk]

Since rustc 1.61, the following code is not giving a compile-time error:

fn main() {
    let xs = [10, 20, 30];
    println!("{}", xs[10]);

    let _n = xs.len();
}

If I uncomment the last line, the compile-time error shows up.
Is this right? I would expect the compile-time error to show up in both cases (this is what happens for rustc < 1.61).

cc @oli-obk

Originally posted by @paolieri in #48920 (comment)

[steffahn]

@rustbot label A-lint, regression-from-stable-to-stable

For context, the “error” pre-1.61 is the deny-by-default unconditional_panic lint

error: this operation will panic at runtime
 --> <source>:3:20
  |
3 |     println!("{}", xs[10]);
  |                    ^^^^^^ index out of bounds: the length is 3 but the index is 10
  |
  = note: `#[deny(unconditional_panic)]` on by default

error: aborting due to previous error

Bisection points to regression in #94934.

[Dajamante]

@rustbot claim

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-high T-compiler