Add regression test for rust-lang#97986

Author: GuillaumeGomez

src/test/rustdoc-json/generic_impl.rs

@@ -0,0 +1,24 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/97986>.
+
+// @has generic_impl.json
+// @has - "$.index[*][?(@.name=='f')]"
+// @has - "$.index[*][?(@.name=='AssocTy')]"
+// @has - "$.index[*][?(@.name=='AssocConst')]"
+
+pub mod m {
+    pub struct S;
+}
+
+pub trait F {
+    type AssocTy;
+    const AssocConst: usize;
+    fn f() -> m::S;
+}
+
+impl<T> F for T {
+    type AssocTy = u32;
+    const AssocConst: usize = 0;
+    fn f() -> m::S {
+        m::S
+    }
+}