librustc: Convert all uses of assert over to fail_unless!

src/test/run-pass/mod_dir_path.rs

@@ -17,5 +17,5 @@ mod mod_dir_simple {
 }
 
 pub fn main() {
-    assert mod_dir_simple::syrup::foo() == 10;
+    fail_unless!(mod_dir_simple::syrup::foo() == 10);
 }