x86 atomics: Remove unused WANT_FUNCTIONS

This macro has not been in use since commit "inline atomics and allow tied
modules to inline locks" (r335873, f4b3640).

Reviewed by:    markj, kib, emaste, imp
MFC after:      5 days
Sponsored by:   The FreeBSD Foundation
Differential Revision:  https://reviews.freebsd.org/D48061

Author: OlCe2

sys/amd64/include/atomic.h

@@ -385,7 +385,6 @@ ATOMIC_LOADSTORE(long);
 #undef ATOMIC_LOAD
 #undef ATOMIC_STORE
 #undef ATOMIC_LOADSTORE
-#ifndef WANT_FUNCTIONS
 
 /* Read the current value and store a new value in the destination. */
 static __inline u_int
@@ -592,8 +591,6 @@ atomic_swap_long(volatile u_long *p, u_long v)
 #define	atomic_testandset_ptr	atomic_testandset_long
 #define	atomic_testandclear_ptr	atomic_testandclear_long
 
-#endif /* !WANT_FUNCTIONS */
-
 #endif /* !SAN_NEEDS_INTERCEPTORS || SAN_RUNTIME */
 
 #endif /* !_MACHINE_ATOMIC_H_ */

sys/i386/include/atomic.h

@@ -299,17 +299,6 @@ atomic_thread_fence_seq_cst(void)
 
 #ifdef _KERNEL
 
-#ifdef WANT_FUNCTIONS
-int		atomic_cmpset_64_i386(volatile uint64_t *, uint64_t, uint64_t);
-int		atomic_cmpset_64_i586(volatile uint64_t *, uint64_t, uint64_t);
-uint64_t	atomic_load_acq_64_i386(const volatile uint64_t *);
-uint64_t	atomic_load_acq_64_i586(const volatile uint64_t *);
-void		atomic_store_rel_64_i386(volatile uint64_t *, uint64_t);
-void		atomic_store_rel_64_i586(volatile uint64_t *, uint64_t);
-uint64_t	atomic_swap_64_i386(volatile uint64_t *, uint64_t);
-uint64_t	atomic_swap_64_i586(volatile uint64_t *, uint64_t);
-#endif
-
 /* I486 does not support SMP or CMPXCHG8B. */
 static __inline int
 atomic_cmpset_64_i386(volatile uint64_t *dst, uint64_t expect, uint64_t src)
@@ -618,8 +607,6 @@ ATOMIC_LOADSTORE(long);
 #undef ATOMIC_STORE
 #undef ATOMIC_LOADSTORE
 
-#ifndef WANT_FUNCTIONS
-
 static __inline int
 atomic_cmpset_long(volatile u_long *dst, u_long expect, u_long src)
 {
@@ -874,8 +861,6 @@ atomic_swap_long(volatile u_long *p, u_long v)
 #define	atomic_testandset_ptr(p, val) \
 	atomic_testandset_int((volatile u_int *)(p), (val))
 
-#endif /* !WANT_FUNCTIONS */
-
 #if defined(_KERNEL)
 #define	mb()	__mbk()
 #define	wmb()	__mbk()