Add regression test for #115480

Author: GuillaumeGomez

tests/rustdoc-js/auxiliary/equivalent.rs

@@ -0,0 +1,15 @@
+use std::borrow::Borrow;
+
+pub trait Equivalent<K: ?Sized> {
+    fn equivalent(&self, key: &K) -> bool;
+}
+
+impl<Q: ?Sized, K: ?Sized> Equivalent<K> for Q
+where
+    Q: Eq,
+    K: Borrow<Q>,
+{
+    fn equivalent(&self, key: &K) -> bool {
+        PartialEq::eq(self, key.borrow())
+    }
+}

tests/rustdoc-js/search-non-local-trait-impl.js

@@ -0,0 +1,9 @@
+// exact-check
+
+// This test ensures that methods from blanket impls of not available foreign traits
+// don't show up in the search results.
+
+const EXPECTED = {
+    'query': 'equivalent',
+    'others': [],
+};

tests/rustdoc-js/search-non-local-trait-impl.rs

@@ -0,0 +1,4 @@
+// aux-build:equivalent.rs
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct LayoutError;