`rustc_has_incoherent_impl` breaks rustdoc in subtle ways

Code

I tried this code:

/// [`std::io::Error::last_os_error`]
pub struct Strukt;

I expected to see this happen: cargo doc finishes without warnings.

Instead, this happened:

warning: unresolved link to `std::io::Error::last_os_error`
 --> dep/src/lib.rs:3:7
  |
3 | /// [`std::io::Error::last_os_error`].
  |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the struct `Error` has no field or associated item named `last_os_error`
  |
  = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

warning: `dep` (lib doc) generated 1 warning

Version it worked on

It most recently worked on: 1.97

Version with regression

rustc --version --verbose:

rustc 1.98.0 (88d9e12ae 2026-08-18)
binary: rustc
commit-hash: 88d9e12ae178fab0fb5cc050a94da85685d449ea
commit-date: 2026-08-18
host: x86_64-unknown-linux-gnu
release: 1.98.0
LLVM version: 22.1.8