Remove two green threading tests

src/test/run-pass/extern-stress.rs

-// Copyright 2012 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.
-
-// This creates a bunch of descheduling tasks that run concurrently
-// while holding onto C stacks
-
-extern crate libc;
-use std::thread::Thread;
-
-mod rustrt {
-    extern crate libc;
-
-    #[link(name = "rust_test_helpers")]
-    extern {
-        pub fn rust_dbg_call(cb: extern "C" fn(libc::uintptr_t) -> libc::uintptr_t,
-                             data: libc::uintptr_t)
-                             -> libc::uintptr_t;
-    }
-}
-
-extern fn cb(data: libc::uintptr_t) -> libc::uintptr_t {
-    if data == 1 {
-        data
-    } else {
-        Thread::yield_now();
-        count(data - 1) + count(data - 1)
-    }
-}
-
-fn count(n: libc::uintptr_t) -> libc::uintptr_t {
-    unsafe {
-        rustrt::rust_dbg_call(cb, n)
-    }
-}
-
-pub fn main() {
-    (0_usize..100).map(|_| {
-        Thread::scoped(move|| {
-            assert_eq!(count(5), 16);
-        })
-    }).collect::<Vec<_>>();
-}

src/test/run-pass/extern-yield.rs

-// Copyright 2012 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.
-
-extern crate libc;
-use std::thread::Thread;
-
-mod rustrt {
-    extern crate libc;
-
-    #[link(name = "rust_test_helpers")]
-    extern {
-        pub fn rust_dbg_call(cb: extern "C" fn (libc::uintptr_t) -> libc::uintptr_t,
-                             data: libc::uintptr_t)
-                             -> libc::uintptr_t;
-    }
-}
-
-extern fn cb(data: libc::uintptr_t) -> libc::uintptr_t {
-    if data == 1 {
-        data
-    } else {
-        count(data - 1) + count(data - 1)
-    }
-}
-
-fn count(n: libc::uintptr_t) -> libc::uintptr_t {
-    unsafe {
-        Thread::yield_now();
-        rustrt::rust_dbg_call(cb, n)
-    }
-}
-
-pub fn main() {
-    (0..10_usize).map(|i| {
-        Thread::scoped(move|| {
-            let result = count(5);
-            println!("result = {}", result);
-            assert_eq!(result, 16);
-        })
-    }).collect::<Vec<_>>();
-}