normalize the self-type that we extract from impl

src/test/ui/nll/user-annotations/normalize-self-ty.rs

@@ -0,0 +1,25 @@
+// Regression test for #55183: check a case where the self type from
+// the inherent impl requires normalization to be equal to the
+// user-provided type.
+//
+// run-pass
+
+#![feature(nll)]
+
+trait Mirror {
+    type Me;
+}
+
+impl<T> Mirror for T {
+    type Me = T;
+}
+
+struct Foo<A, B>(A, B);
+
+impl<A> Foo<A, <A as Mirror>::Me> {
+    fn m(b: A) { }
+}
+
+fn main() {
+    <Foo<&'static u32, &u32>>::m(&22);
+}