Add .use block test

tests/ui/ergonomic-clones/dotuse/block.rs

@@ -0,0 +1,11 @@
+//@ check-pass
+
+#![feature(ergonomic_clones)]
+#![allow(incomplete_features)]
+
+fn use_block_test(x: i32) -> i32 {
+    let x = { let x = x + 1; x }.use;
+    x
+}
+
+fn main() {}