add a test for #104260

Author: TaKO8Ki

src/test/ui/associated-inherent-types/issue-104260.rs

@@ -0,0 +1,14 @@
+// check-pass
+
+#![feature(inherent_associated_types)]
+#![allow(incomplete_features)]
+
+struct Foo;
+
+impl Foo {
+    type Bar<T> = u8;
+}
+
+fn main() {
+    let a: Foo::Bar<()>;
+}