tests: add regression test for #74614

This commit adds a regression test for #74614 so that it is fixed before
polymorphisation is re-enabled.

Signed-off-by: David Wood <david@davidtw.co>

src/test/ui/issues/issue-74614.rs

@@ -0,0 +1,17 @@
+// build-pass
+
+fn test<T>() {
+    std::mem::size_of::<T>();
+}
+
+pub fn foo<T>(_: T) -> &'static fn() {
+    &(test::<T> as fn())
+}
+
+fn outer<T>() {
+    foo(|| ());
+}
+
+fn main() {
+    outer::<u8>();
+}