Un-xfail working test cases

Author: catamorphism

src/test/run-fail/alt-bot-fail.rs

@@ -1,7 +1,4 @@
-// xfail-stage0
-// xfail-stage1
-// xfail-stage2
-// xfail-stage3
+// error-pattern:explicit failure
 use std;
 import std::option::*;
 
@@ -18,4 +15,4 @@ fn main() {
     }
   };
   foo(i);
-}
+}

src/test/run-fail/expr-fn-fail.rs

@@ -1,4 +1,3 @@
-// xfail-stage0
 // error-pattern:explicit failure
 
 fn f() -> ! { fail }