test: Add a version of the "mock-trans" regions test case that uses impls

src/test/run-pass/regions-mock-trans-impls.rs

@@ -0,0 +1,46 @@
+import libc, sys, unsafe;
+
+enum arena = ();
+
+type bcx = {
+    fcx: &fcx
+};
+
+type fcx = {
+    arena: &arena,
+    ccx: &ccx
+};
+
+type ccx = {
+    x: int
+};
+
+impl arena for arena {
+    fn alloc(sz: uint, _align: uint) -> *() unsafe {
+        ret unsafe::reinterpret_cast(libc::malloc(sz));
+    }
+}
+
+fn h(bcx : &bcx) -> &bcx {
+    ret new(*bcx.fcx.arena) { fcx: fcx };
+}
+
+fn g(fcx : &fcx) {
+    let bcx = { fcx: fcx };
+    let bcx2 = h(&bcx);
+    unsafe {
+        libc::free(unsafe::reinterpret_cast(bcx2));
+    }
+}
+
+fn f(ccx : &ccx) {
+    let a = arena(());
+    let fcx = { arena: &a, ccx: ccx };
+    ret g(&fcx);
+}
+
+fn main() {
+    let ccx = { x: 0 };
+    f(&ccx);
+}
+