[Ada] Fix retrieval of number of CPUs on QNX

Although the sysconf SC_NPROCESSORS_ONLN is also defined by the API, the
only documented way to retrieve the number of CPUs is by using the syspage.

This also better organise the QNX-specific macros in adaint.c

2018-05-22  Jerome Lambourg  <lambourg@adacore.com>

gcc/ada/

	* adaint.c: Reorganize QNX-specific macros, use syspage to retreive the
	number of CPUs.

From-SVN: r260531

gcc/ada/ChangeLog

 2018-05-22  Jerome Lambourg  <lambourg@adacore.com>
 
+	* adaint.c: Reorganize QNX-specific macros, use syspage to retreive the
+	number of CPUs.
+
+2018-05-22  Jerome Lambourg  <lambourg@adacore.com>
+
 	* sigtramp-qnx.c: Properly restore link register in signal trampoline.
 
 2018-05-22  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/adaint.c

@@ -39,7 +39,9 @@
 #define _THREAD_SAFE
 
 /* Use 64 bit Large File API */
-#ifndef _LARGEFILE_SOURCE
+#if defined (__QNX__)
+#define _LARGEFILE64_SOURCE 1
+#elif !defined(_LARGEFILE_SOURCE)
 #define _LARGEFILE_SOURCE
 #endif
 #define _FILE_OFFSET_BITS 64
@@ -81,8 +83,8 @@
 #define __BSD_VISIBLE 1
 #endif
 
-#if defined (__QNX__)
-#define _LARGEFILE64_SOURCE 1
+#ifdef __QNX__
+#include <sys/syspage.h>
 #endif
 
 #ifdef IN_RTS
@@ -2350,9 +2352,12 @@ __gnat_number_of_cpus (void)
 
 #if defined (__linux__) || defined (__sun__) || defined (_AIX) \
   || defined (__APPLE__) || defined (__FreeBSD__) || defined (__OpenBSD__) \
-  || defined (__DragonFly__) || defined (__NetBSD__) || defined (__QNX__)
+  || defined (__DragonFly__) || defined (__NetBSD__)
   cores = (int) sysconf (_SC_NPROCESSORS_ONLN);
 
+#elif defined (__QNX__)
+  cores = (int) _syspage_ptr->num_cpu;
+
 #elif defined (__hpux__)
   struct pst_dynamic psd;
   if (pstat_getdynamic (&psd, sizeof (psd), 1, 0) != -1)