Type with StructuralPartialEq impl with unsatisfied lifetime bounds can be used as const pattern

I tried this code:

#![feature(structural_match)]

struct Thing;

trait IsStatic {}
impl<'a: 'static> IsStatic for &'a () {}

impl std::marker::StructuralPartialEq for Thing where for<'a> &'a (): IsStatic {}

impl PartialEq for Thing
where
    for<'a> &'a (): IsStatic,
{
    fn eq(&self, _: &Thing) -> bool {
        panic!()
    }
}

const A: Thing = Thing;

fn main() {
    let A = Thing;
}

In this code, the for<'a> &'a (): IsStatic bound is unsatisfied. Therefore, the Thing type implements neither StructuralPartialEq nor PartialEq. Therefore, this code should not compile. However, the code compiles without errors, which seems wrong.

There's this comment in the compiler which seems relevant: https://github.com/rust-lang/rust/blob/2e667b0c6491678642a83e3aff86626397360af5/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs#L503-L512

See also https://github.com/rust-lang/rust/issues/147714, which involves an incorrect StructuralPartialEq impl from derive(PartialEq).

Meta

Reproducible on the playground with version 1.94.0-nightly (2025-12-09 c61a3a44d1a5bee35914)

Reproduce the supplied example with the stated nightly compiler, then inspect compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs around the referenced comment. Trace how StructuralPartialEq and the unsatisfied higher-ranked lifetime bound are handled for const patterns. Done means the example is rejected consistently with the missing trait implementations, with regression coverage for this case.