test: Add a simple region test, xfail'd in the pretty printer

src/test/run-pass/simple-regions.rs

@@ -0,0 +1,12 @@
+// xfail-pretty
+
+fn main() {
+    unsafe {
+        let x : int = 3;
+        let y : &mut int = &mut x;
+        *y = 5;
+        log(debug, *y);
+    }
+}
+
+