Revert changes made to rmake.rs

Author: NobodyXu

tests/run-make/broken-pipe-no-ice/rmake.rs

@@ -11,6 +11,8 @@
 // Internal Compiler Error strangely, but it doesn't even go through normal diagnostic infra. Very
 // strange.
 
+#![feature(anonymous_pipe)
+
 use std::io::Read;
 use std::process::{Command, Stdio};