compile-pass test for rust-lang#53606

Author: Saleem Jaffer

src/test/ui/consts/promote_evaluation_unused_result.rs

@@ -0,0 +1,8 @@
+//compile-pass
+
+#![feature(nll)]
+
+fn main() {
+
+    let _: &'static usize = &(loop {}, 1).1;
+}