lib: posix: Fix compile issue with newer newlib

Both SDK 0.10.0-beta2 and the ARM gcc 2018q2 run into a build issue with
newlib and conflict definitions of mode_t type.

First we need to add some ifdef protection if mode_t is already defined
and set _MODE_T_DECLARED if we are the first to define it.

Secondarily, we rename include/posix/sys/types.h to
include/posix/posix_types.h so that we aren't getting a name collusion
with the system sys/types.h and that we can easily and clearily include
it (which we need to do to pull in the info from newlib).

Fixes: #12224

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>

include/posix/dirent.h

@@ -11,7 +11,7 @@ extern "C" {
 #endif
 
 #include <limits.h>
-#include "sys/types.h"
+#include "posix_types.h"
 
 #ifdef CONFIG_POSIX_FS
 #include <fs.h>

include/posix/mqueue.h

@@ -9,7 +9,7 @@
 
 #include <kernel.h>
 #include <posix/time.h>
-#include "sys/types.h"
+#include "posix_types.h"
 #include "sys/stat.h"
 
 #ifdef __cplusplus

include/posix/posix_types.h

@@ -12,7 +12,7 @@ extern "C" {
 #endif
 
 #ifndef CONFIG_ARCH_POSIX
-#include_next <sys/types.h>
+#include <sys/types.h>
 #endif
 
 #include <kernel.h>

include/posix/pthread.h

@@ -11,7 +11,7 @@
 #include <wait_q.h>
 #include <posix/time.h>
 #include <posix/unistd.h>
-#include "sys/types.h"
+#include "posix_types.h"
 #include "posix_sched.h"
 #include <posix/pthread_key.h>
 #include <stdlib.h>

include/posix/semaphore.h

@@ -11,7 +11,7 @@ extern "C" {
 #endif
 
 #include <posix/time.h>
-#include "sys/types.h"
+#include "posix_types.h"
 
 int sem_destroy(sem_t *semaphore);
 int sem_getvalue(sem_t *restrict semaphore, int *restrict value);

include/posix/signal.h

@@ -10,7 +10,7 @@
 extern "C" {
 #endif
 
-#include "sys/types.h"
+#include "posix_types.h"
 
 #ifndef SIGEV_NONE
 #define SIGEV_NONE 1

include/posix/time.h

@@ -27,7 +27,7 @@ struct timeval {
 
 #include <kernel.h>
 #include <errno.h>
-#include <sys/types.h>
+#include "posix_types.h"
 #include <posix/signal.h>
 
 #ifndef CLOCK_REALTIME

include/posix/unistd.h

@@ -10,13 +10,16 @@
 extern "C" {
 #endif
 
-#include "sys/types.h"
+#include "posix_types.h"
 #include "sys/stat.h"
 
 #ifdef CONFIG_POSIX_API
 #include <fs.h>
 
+#ifndef _MODE_T_DECLARED
 typedef unsigned int mode_t;
+#define _MODE_T_DECLARED
+#endif
 
 /* File related operations */
 extern int open(const char *name, int flags);