Moved compile-fail tests to ui tests.

src/test/compile-fail/feature-gate-alloc-error-handler.rs

@@ -1,21 +0,0 @@
-// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// compile-flags:-C panic=abort
-
-#![no_std]
-#![no_main]
-
-use core::alloc::Layout;
-
-#[alloc_error_handler] //~ ERROR #[alloc_error_handler] is an unstable feature (see issue #51540)
-fn oom(info: Layout) -> ! {
-    loop {}
-}