Add comments explaining why these tests are xfailed

src/test/auxiliary/cci_class_5.rs

@@ -1,20 +1,15 @@
 mod kitties {
-    #[legacy_exports];
 
-struct cat {
-  priv {
-    mut meows : uint,
-  }
-
-  how_hungry : int,
-
-}
-
-    impl cat {
-      priv fn nap() { for uint::range(1u, 10000u) |_i|{}}
+    pub struct cat {
+        priv mut meows : uint,
+        how_hungry : int,
     }
 
-    fn cat(in_x : uint, in_y : int) -> cat {
+    impl cat {
+      priv fn nap() { for uint::range(1, 10000u) |_i|{}}
+    }
+
+    pub fn cat(in_x : uint, in_y : int) -> cat {
         cat {
             meows: in_x,
             how_hungry: in_y

src/test/compile-fail/omitted-arg-wrong-types.rs

@@ -1,5 +1,4 @@
-// xfail-test
-
+// xfail-test - #2093
 fn let_in<T>(x: T, f: fn(T)) {}
 
 fn main() {

src/test/compile-fail/private-method-cross-crate.rs

@@ -1,11 +1,11 @@
 // error-pattern:attempted access of field `nap` on type
+// xfail-test Cross-crate impl method privacy doesn't work
 // xfail-fast
-// xfail-test
 // aux-build:cci_class_5.rs
-use cci_class_5;
+extern mod cci_class_5;
 use cci_class_5::kitties::*;
 
 fn main() {
-  let nyan : cat = cat(52u, 99);
+  let nyan : cat = cat(52, 99);
   nyan.nap();
 }

src/test/compile-fail/regions-out-of-scope-slice.rs

@@ -1,12 +1,11 @@
-// xfail-test
-
+// xfail-test blk region isn't supported in the front-end
 fn foo(cond: bool) {
     // Here we will infer a type that uses the
     // region of the if stmt then block, but in the scope:
     let mut x; //~ ERROR foo
 
     if cond {
-        x = &[1,2,3]blk;
+        x = &blk/[1,2,3];
     }
 }