[AD] Missing include for aintern.h?

[Evert Glebbeek <eglebbk@xxxxxxxxxx>]

Compiling 4.2.1 SVN resulted in complaints about missing _AL_FREE's and the 
like. I fixed that by adding #include "allegro/internal/aintern.h", which 
was apparently missing. Patch attached, but I'd like to hear a little bit 
more about the background of this error (ie, that it isn't a case of the 
build system acting up).

Evert

Index: src/linux/ljoy.c
===================================================================
--- src/linux/ljoy.c	(revision 5662)
+++ src/linux/ljoy.c	(working copy)
@@ -28,6 +28,7 @@
 
 #include "allegro.h"
 #include "allegro/platform/aintunix.h"
+#include "allegro/internal/aintern.h"
 
 
 #ifdef HAVE_LINUX_JOYSTICK_H
Index: src/unix/uthreads.c
===================================================================
--- src/unix/uthreads.c	(revision 5662)
+++ src/unix/uthreads.c	(working copy)
@@ -20,6 +20,7 @@
 
 #include "allegro.h"
 #include "allegro/platform/aintunix.h"
+#include "allegro/internal/aintern.h"
 
 #ifdef HAVE_LIBPTHREAD