libspl: move compiler attribute macros from zfs_context.h

sys/debug.h is not really the right place for them, but we already have
some there for libspl, so it is at least convenient.

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #17861

Author: robn

include/sys/zfs_context.h

@@ -133,14 +133,6 @@ extern "C" {
 
 #include <sys/zfs_context_os.h>
 
-/*
- * Stack
- */
-
-#define	noinline	__attribute__((noinline))
-#define	likely(x)	__builtin_expect((x), 1)
-#define	unlikely(x)	__builtin_expect((x), 0)
-
 #ifdef __FreeBSD__
 typedef off_t loff_t;
 #endif

lib/libspl/include/sys/debug.h

@@ -24,6 +24,12 @@
  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2012, Joyent, Inc. All rights reserved.
+ */
 
 #ifndef _LIBSPL_SYS_DEBUG_H
 #define	_LIBSPL_SYS_DEBUG_H
@@ -42,4 +48,16 @@
 #define	__must_check __attribute__((warn_unused_result))
 #endif
 
+#ifndef noinline
+#define	noinline	__attribute__((noinline))
+#endif
+
+#ifndef likely
+#define	likely(x)	__builtin_expect((x), 1)
+#endif
+
+#ifndef unlikely
+#define	unlikely(x)	__builtin_expect((x), 0)
+#endif
+
 #endif