add fixme in typoed const pattern lint

Author: lqd

compiler/rustc_mir_build/src/thir/pattern/check_match.rs

@@ -1086,6 +1086,12 @@ fn find_fallback_pattern_typo<'tcx>(
                 let vis = cx.tcx.visibility(item.owner_id);
                 if vis.is_accessible_from(parent, cx.tcx) {
                     accessible.push(item_name);
+                    // FIXME: the line below from PR #135310 is a workaround for the ICE in issue
+                    // #135289, where a macro in a dependency can create unreachable patterns in the
+                    // current crate. Path trimming expects diagnostics for a typoed const, but no
+                    // diagnostics are emitted and we ICE. See
+                    // `tests/ui/resolve/const-with-typo-in-pattern-binding-ice-135289.rs` for a
+                    // test that reproduces the ICE if we don't use `with_no_trimmed_paths!`.
                     let path = with_no_trimmed_paths!(cx.tcx.def_path_str(item.owner_id));
                     accessible_path.push(path);
                 } else if name == item_name {