Header refactoring: unify spin.h and move it out of the catch-all.

src/extent_dss.c

@@ -3,6 +3,7 @@
 #include "jemalloc/internal/jemalloc_internal_includes.h"
 
 #include "jemalloc/internal/assert.h"
+#include "jemalloc/internal/spin.h"
 
 /******************************************************************************/
 /* Data. */

src/jemalloc.c

@@ -6,6 +6,7 @@
 #include "jemalloc/internal/atomic.h"
 #include "jemalloc/internal/jemalloc_internal_types.h"
 #include "jemalloc/internal/malloc_io.h"
+#include "jemalloc/internal/spin.h"
 #include "jemalloc/internal/util.h"
 
 /******************************************************************************/

src/spin.c

@@ -1,3 +1,4 @@
 #define JEMALLOC_SPIN_C_
 #include "jemalloc/internal/jemalloc_preamble.h"
-#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/spin.h"