Voucher portability fixes.

* The `VOUCHER_USE_MACH_VOUCHER` branch defines `_voucher_atfork_parent`
  but the `#else` branch does not. Assume it should look like the
  implementation for `_voucher_atfork_child` nearby.

* Compiler complains about `voucher_process_can_use_arbitrary_personas`
  not having a previous prototype. This actually isn't used anywhere
  outside the `VOUCHER_USE_MACH_VOUCHER` branch, so remove it.

* Ensure `voucher_needs_adopt` is `static` inline, otherwise the linker
  gives "multiple definition" errors despite it being marked as inline.

Author: 3405691582

dispatch/base.h

@@ -62,7 +62,7 @@
 #define DISPATCH_CONST __attribute__((__const__))
 #define DISPATCH_WARN_RESULT __attribute__((__warn_unused_result__))
 #define DISPATCH_MALLOC __attribute__((__malloc__))
-#define DISPATCH_ALWAYS_INLINE __attribute__((__always_inline__))
+#define DISPATCH_ALWAYS_INLINE __attribute__((unused, __always_inline__))
 #define DISPATCH_UNAVAILABLE __attribute__((__unavailable__))
 #define DISPATCH_UNAVAILABLE_MSG(msg) __attribute__((__unavailable__(msg)))
 #elif defined(_MSC_VER)

os/voucher_private.h

@@ -128,14 +128,15 @@ voucher_adopt(voucher_t _Nullable voucher OS_OBJECT_CONSUMED);
  */
 
 SPI_AVAILABLE(macos(12.0), ios(15.0))
-DISPATCH_ALWAYS_INLINE bool
+DISPATCH_ALWAYS_INLINE static bool
 voucher_needs_adopt(voucher_t _Nullable voucher)
 {
 #if __APPLE__
 	if (_pthread_has_direct_tsd()) {
 		return (((void *) voucher) != _pthread_getspecific_direct(OS_VOUCHER_TSD_KEY));
 	}
 #endif
+	(void)voucher;
 	return true;
 }
 

src/voucher.c

@@ -1987,14 +1987,13 @@ voucher_get_current_persona_proximate_info(struct proc_persona_info *persona_inf
 }
 #endif // __has_include(<mach/mach.h>)
 
-bool
-voucher_process_can_use_arbitrary_personas(void)
+void
+_voucher_activity_debug_channel_init(void)
 {
-	return false;
 }
 
 void
-_voucher_activity_debug_channel_init(void)
+_voucher_atfork_parent(void)
 {
 }