Consider unop deref as an lval. Un-XFAIL vec-push.

src/comp/middle/ty.rs

@@ -1958,6 +1958,7 @@ fn is_lval(@ast.expr expr) -> bool {
         case (ast.expr_field(_,_,_))    { ret true;  }
         case (ast.expr_index(_,_,_))    { ret true;  }
         case (ast.expr_path(_,_,_))     { ret true;  }
+        case (ast.expr_unary(ast.deref,_,_))  { ret true; }
         case (_)                        { ret false; }
     }
 }

src/test/run-pass/vec-push.rs

@@ -1,11 +1,9 @@
-// xfail-stage0
-
 fn push[T](&mutable vec[mutable? T] v, &T t) {
     v += vec(t);
 }
 
 fn main() {
     auto v = @vec(1, 2, 3);
-    push(*v, 1);
+    push[int](*v, 1);
 }