Move /src/test to /tests

tests/ui/zero-sized/zero-sized-tuple-struct.rs

@@ -0,0 +1,13 @@
+// run-pass
+#![allow(unused_braces)]
+#![allow(unused_assignments)]
+
+// Make sure that the constructor args are codegened for zero-sized tuple structs
+
+struct Foo(());
+
+fn main() {
+    let mut a = 1;
+    Foo({ a = 2 });
+    assert_eq!(a, 2);
+}