Moved problematic tests on x86_64-pc-windows-gnu back to compile-fail.

src/test/compile-fail/auxiliary/some-panic-impl.rs

@@ -0,0 +1,22 @@
+// 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.
+
+// no-prefer-dynamic
+
+#![crate_type = "rlib"]
+#![feature(panic_implementation)]
+#![no_std]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(info: &PanicInfo) -> ! {
+    loop {}
+}

src/test/compile-fail/auxiliary/weak-lang-items.rs

@@ -0,0 +1,32 @@
+// Copyright 2014 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.
+
+// no-prefer-dynamic
+
+// This aux-file will require the eh_personality function to be codegen'd, but
+// it hasn't been defined just yet. Make sure we don't explode.
+
+#![no_std]
+#![crate_type = "rlib"]
+
+struct A;
+
+impl core::ops::Drop for A {
+    fn drop(&mut self) {}
+}
+
+pub fn foo() {
+    let _a = A;
+    panic!("wut");
+}
+
+mod std {
+    pub use core::{option, fmt};
+}