Add regression test for rust-lang#104064

Author: GuillaumeGomez

src/test/rustdoc-json/primitives/local_primitive.rs

@@ -0,0 +1,21 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/104064>.
+
+#![feature(no_core)]
+#![feature(rustc_attrs)]
+#![feature(rustdoc_internals)]
+#![no_core]
+#![rustc_coherence_is_core]
+
+//! Link to [i32][prim@i32] [i64][prim@i64]
+
+#[doc(primitive = "i32")]
+mod prim_i32 {}
+
+// @set local_i32 = "$.index[*][?(@.name=='i32')].id"
+
+// @has "$.index[*][?(@.name=='local_primitive')]"
+// @ismany "$.index[*][?(@.name=='local_primitive')].inner.items[*]" $local_i32
+// @is "$.index[*][?(@.name=='local_primitive')].links['prim@i32']" $local_i32
+
+// Let's ensure the `prim_i32` module isn't present in the output JSON:
+// @!has "$.index[*][?(@.name=='prim_i32')]"