new test case demonstrating ability to return ptr to interior of option

src/test/run-pass/region-return-interior-of-option.rs

@@ -0,0 +1,22 @@
+fn get<T>(opt: &option<T>) -> &T {
+    match *opt {
+      some(ref v) => v,
+      none => fail ~"none"
+    }
+}
+
+fn main() {
+    let mut x = some(23);
+
+    {
+        let y = get(&x);
+        assert *y == 23;
+    }
+
+    x = some(24);
+
+    {
+        let y = get(&x);
+        assert *y == 24;
+    }
+}