mm/headers, sched/headers: Prepare to split <linux/mm_types_task.h> out of <linux/mm_types.h>

We are going to separate all the MM types that are embedded directly in 'struct task_struct'
into the new <linux/mm_types_task.h> header.

Create a new <linux/mm_types_task.h> that only contains some includes from mm_types.h itself.

This should be trivially correct and easy to bisect to.

(This patch does not materially move the types yet.)

Acked-by: Linus Torvalds <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

include/linux/mm_types.h

···
 #ifndef _LINUX_MM_TYPES_H
 #define _LINUX_MM_TYPES_H
 
+#include <linux/mm_types_task.h>
+
 #include <linux/auxvec.h>
-#include <linux/types.h>
-#include <linux/threads.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/rbtree.h>
···
 #include <linux/uprobes.h>
 #include <linux/page-flags-layout.h>
 #include <linux/workqueue.h>
-#include <asm/page.h>
+
 #include <asm/mmu.h>
 
 #ifndef AT_VECTOR_SIZE_ARCH

include/linux/mm_types_task.h

···
+#ifndef _LINUX_MM_TYPES_TASK_H
+#define _LINUX_MM_TYPES_TASK_H
+
+#include <linux/types.h>
+#include <linux/threads.h>
+#include <linux/atomic.h>
+
+#include <asm/page.h>
+
+#endif /* _LINUX_MM_TYPES_TASK_H */