Haiku: Revert "std: Handle OS errors when joining threads"

This reverts commit dc7c7ba.

There is an issue with threading in cargo, where thread::join fails after completing a build. This prevents building Rust on Haiku (as the build system kills itself after failure).

The problem is documented at rust-on-haiku.com issue #10

src/libstd/sys/unix/thread.rs

@@ -175,8 +175,7 @@ impl Thread {
         unsafe {
             let ret = libc::pthread_join(self.id, ptr::null_mut());
             mem::forget(self);
-            assert!(ret == 0,
-                    "failed to join thread: {}", io::Error::from_raw_os_error(ret));
+            debug_assert_eq!(ret, 0);
         }
     }
 

src/libstd/sys/windows/c.rs

@@ -269,7 +269,6 @@ pub const FILE_END: DWORD = 2;
 
 pub const WAIT_OBJECT_0: DWORD = 0x00000000;
 pub const WAIT_TIMEOUT: DWORD = 258;
-pub const WAIT_FAILED: DWORD = 0xFFFFFFFF;
 
 #[cfg(target_env = "msvc")]
 #[cfg(feature = "backtrace")]

src/libstd/sys/windows/thread.rs

@@ -66,11 +66,7 @@ impl Thread {
     }
 
     pub fn join(self) {
-        let rc = unsafe { c::WaitForSingleObject(self.handle.raw(), c::INFINITE) };
-        if rc == c::WAIT_FAILED {
-            panic!("failed to join on thread: {}",
-                   io::Error::last_os_error());
-        }
+        unsafe { c::WaitForSingleObject(self.handle.raw(), c::INFINITE); }
     }
 
     pub fn yield_now() {

src/libstd/thread/mod.rs

@@ -1303,11 +1303,6 @@ impl<T> JoinHandle<T> {
     /// [`Err`]: ../../std/result/enum.Result.html#variant.Err
     /// [`panic`]: ../../std/macro.panic.html
     ///
-    /// # Panics
-    ///
-    /// This function may panic on some platforms if a thread attempts to join
-    /// itself or otherwise may create a deadlock with joining threads.
-    ///
     /// # Examples
     ///
     /// ```