attempt codegen test conversion

tests/codegen/noalias-freeze.rs

@@ -0,0 +1,21 @@
+//@ compile-flags: -Copt-level=1
+
+// References returned by a Frozen pointer type
+// could be marked as "noalias", which caused miscompilation errors.
+// This test runs the most minimal possible code that can reproduce this bug,
+// and checks that noalias does not appear.
+// See https://github.com/rust-lang/rust/issues/46239
+
+#![crate_type = "lib"]
+
+fn project<T>(x: &(T,)) -> &T { &x.0 }
+
+fn dummy() {}
+
+// CHECK-LABEL: @foo(
+// CHECK-NOT: noalias
+#[no_mangle]
+pub fn foo() {
+    let f = (dummy as fn(),);
+    (*project(&f))();
+}