Duplicate OSAtomic.h between aarch64 and x86_64

The reason this is required is for two reasons: 1) the libc
targeting `aarch64` macOS is slightly newer than that targeting
`x86_64`, and 2) `OSAtomic.h` uses relative imports rather than
system-wide imports for accompanying headers which clearly is an
oversight on Apple's part. Until such time when `libkern` headers
between `x86_64` and `aarch64` are identical, this will require a
manual intervention to duplicate the relevant headers between the
respective architectures.

lib/libc/include/x86_64-macos-gnu/libkern/OSAtomic.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2004-2016 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#ifndef _OSATOMIC_H_
+#define _OSATOMIC_H_
+
+/*! @header
+ * These are deprecated legacy interfaces for atomic and synchronization
+ * operations.
+ *
+ * Define OSATOMIC_USE_INLINED=1 to get inline implementations of the
+ * OSAtomic interfaces in terms of the <stdatomic.h> primitives.
+ *
+ * Define OSSPINLOCK_USE_INLINED=1 to get inline implementations of the
+ * OSSpinLock interfaces in terms of the <os/lock.h> primitives.
+ *
+ * These are intended as a transition convenience, direct use of those
+ * primitives should be preferred.
+ */
+
+#include <sys/cdefs.h>
+
+#include "OSAtomicDeprecated.h"
+#include "OSSpinLockDeprecated.h"
+#include "OSAtomicQueue.h"
+
+#endif /* _OSATOMIC_H_ */

lib/libc/include/x86_64-macos-gnu/libkern/OSSpinLockDeprecated.h

@@ -0,0 +1,212 @@
+/*
+ * Copyright (c) 2004-2016 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#ifndef _OSSPINLOCK_DEPRECATED_H_
+#define _OSSPINLOCK_DEPRECATED_H_
+
+/*! @header
+ * These are deprecated legacy interfaces for userspace spinlocks.
+ *
+ * These interfaces should no longer be used, particularily in situations where
+ * threads of differing priorities may contend on the same spinlock.
+ *
+ * The interfaces in <os/lock.h> should be used instead in cases where a very
+ * low-level lock primitive is required. In general however, using higher level
+ * synchronization primitives such as those provided by the pthread or dispatch
+ * subsystems should be preferred.
+ *
+ * Define OSSPINLOCK_USE_INLINED=1 to get inline implementations of these
+ * interfaces in terms of the <os/lock.h> primitives. This is intended as a
+ * transition convenience, direct use of those primitives is preferred.
+ */
+
+#ifndef OSSPINLOCK_DEPRECATED
+#define OSSPINLOCK_DEPRECATED 1
+#define OSSPINLOCK_DEPRECATED_MSG(_r) "Use " #_r "() from <os/lock.h> instead"
+#define OSSPINLOCK_DEPRECATED_REPLACE_WITH(_r) \
+	__OS_AVAILABILITY_MSG(macosx, deprecated=10.12, OSSPINLOCK_DEPRECATED_MSG(_r)) \
+	__OS_AVAILABILITY_MSG(ios, deprecated=10.0, OSSPINLOCK_DEPRECATED_MSG(_r)) \
+	__OS_AVAILABILITY_MSG(tvos, deprecated=10.0, OSSPINLOCK_DEPRECATED_MSG(_r)) \
+	__OS_AVAILABILITY_MSG(watchos, deprecated=3.0, OSSPINLOCK_DEPRECATED_MSG(_r))
+#else
+#undef OSSPINLOCK_DEPRECATED
+#define OSSPINLOCK_DEPRECATED 0
+#define OSSPINLOCK_DEPRECATED_REPLACE_WITH(_r)
+#endif
+
+#if !(defined(OSSPINLOCK_USE_INLINED) && OSSPINLOCK_USE_INLINED)
+
+#include    <sys/cdefs.h>
+#include    <stddef.h>
+#include    <stdint.h>
+#include    <stdbool.h>
+#include    <Availability.h>
+
+__BEGIN_DECLS
+
+/*! @abstract The default value for an <code>OSSpinLock</code>.
+    @discussion
+	The convention is that unlocked is zero, locked is nonzero.
+ */
+#define	OS_SPINLOCK_INIT    0
+
+
+/*! @abstract Data type for a spinlock.
+    @discussion
+	You should always initialize a spinlock to {@link OS_SPINLOCK_INIT} before
+	using it.
+ */
+typedef int32_t OSSpinLock OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock);
+
+
+/*! @abstract Locks a spinlock if it would not block
+    @result
+	Returns <code>false</code> if the lock was already held by another thread,
+	<code>true</code> if it took the lock successfully.
+ */
+OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_trylock)
+__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0)
+bool    OSSpinLockTry( volatile OSSpinLock *__lock );
+
+
+/*! @abstract Locks a spinlock
+    @discussion
+	Although the lock operation spins, it employs various strategies to back
+	off if the lock is held.
+ */
+OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_lock)
+__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0)
+void    OSSpinLockLock( volatile OSSpinLock *__lock );
+
+
+/*! @abstract Unlocks a spinlock */
+OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_unlock)
+__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0)
+void    OSSpinLockUnlock( volatile OSSpinLock *__lock );
+
+__END_DECLS
+
+#else /* OSSPINLOCK_USE_INLINED */
+
+/*
+ * Inline implementations of the legacy OSSpinLock interfaces in terms of the
+ * of the <os/lock.h> primitives. Direct use of those primitives is preferred.
+ *
+ * NOTE: the locked value of os_unfair_lock is implementation defined and
+ * subject to change, code that relies on the specific locked value used by the
+ * legacy OSSpinLock interface WILL break when using these inline
+ * implementations in terms of os_unfair_lock.
+ */
+
+#if !OSSPINLOCK_USE_INLINED_TRANSPARENT
+
+#include <os/lock.h>
+
+__BEGIN_DECLS
+
+#if __has_attribute(always_inline)
+#define OSSPINLOCK_INLINE static __inline
+#else
+#define OSSPINLOCK_INLINE static __inline __attribute__((__always_inline__))
+#endif
+
+#define OS_SPINLOCK_INIT 0
+typedef int32_t OSSpinLock;
+
+#if  __has_extension(c_static_assert)
+_Static_assert(sizeof(OSSpinLock) == sizeof(os_unfair_lock),
+		"Incompatible os_unfair_lock type");
+#endif
+
+OSSPINLOCK_INLINE
+void
+OSSpinLockLock(volatile OSSpinLock *__lock)
+{
+	os_unfair_lock_t lock = (os_unfair_lock_t)__lock;
+	return os_unfair_lock_lock(lock);
+}
+
+OSSPINLOCK_INLINE
+bool
+OSSpinLockTry(volatile OSSpinLock *__lock)
+{
+	os_unfair_lock_t lock = (os_unfair_lock_t)__lock;
+	return os_unfair_lock_trylock(lock);
+}
+
+OSSPINLOCK_INLINE
+void
+OSSpinLockUnlock(volatile OSSpinLock *__lock)
+{
+	os_unfair_lock_t lock = (os_unfair_lock_t)__lock;
+	return os_unfair_lock_unlock(lock);
+}
+
+#undef OSSPINLOCK_INLINE
+
+__END_DECLS
+
+#else /* OSSPINLOCK_USE_INLINED_TRANSPARENT */
+
+#include    <sys/cdefs.h>
+#include    <stddef.h>
+#include    <stdint.h>
+#include    <stdbool.h>
+#include    <Availability.h>
+
+#define OS_NOSPIN_LOCK_AVAILABILITY \
+		__OSX_AVAILABLE(10.12) __IOS_AVAILABLE(10.0) \
+		__TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0)
+
+__BEGIN_DECLS
+
+#define OS_SPINLOCK_INIT 0
+typedef int32_t OSSpinLock OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock);
+typedef volatile OSSpinLock *_os_nospin_lock_t
+		OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_t);
+
+OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_lock)
+OS_NOSPIN_LOCK_AVAILABILITY
+void _os_nospin_lock_lock(_os_nospin_lock_t lock);
+#undef OSSpinLockLock
+#define OSSpinLockLock(lock) _os_nospin_lock_lock(lock)
+
+OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_trylock)
+OS_NOSPIN_LOCK_AVAILABILITY
+bool _os_nospin_lock_trylock(_os_nospin_lock_t lock);
+#undef OSSpinLockTry
+#define OSSpinLockTry(lock) _os_nospin_lock_trylock(lock)
+
+OSSPINLOCK_DEPRECATED_REPLACE_WITH(os_unfair_lock_unlock)
+OS_NOSPIN_LOCK_AVAILABILITY
+void _os_nospin_lock_unlock(_os_nospin_lock_t lock);
+#undef OSSpinLockUnlock
+#define OSSpinLockUnlock(lock) _os_nospin_lock_unlock(lock)
+
+__END_DECLS
+
+#endif /* OSSPINLOCK_USE_INLINED_TRANSPARENT */
+
+#endif /* OSSPINLOCK_USE_INLINED */
+
+#endif /* _OSSPINLOCK_DEPRECATED_H_ */

src/Compilation.zig

@@ -2888,7 +2888,6 @@ fn buildOutputFromZig(
         .directory = null, // Put it in the cache directory.
         .basename = bin_basename,
     };
-
     const sub_compilation = try Compilation.create(comp.gpa, .{
         .global_cache_directory = comp.global_cache_directory,
         .local_cache_directory = comp.global_cache_directory,