stdlib: Fixing test-*atexit*-race tests on ia64

These tests require a new thread stack size set to a value (0x20000)
lower than the architecture minimum (0x30000).  Set the stack size
to PTHREAD_STACK_MIN in this case.

Checked on ia64-linux-gnu.

	* stdlib/test-atexit-race-common.c (do_test): Check stack size
	against PTHREAD_STACK_MIN.

Author: zatrazz

ChangeLog

@@ -1,3 +1,8 @@
+2018-02-01  Adhemerval Zanella  <[email protected]>
+
+	* stdlib/test-atexit-race-common.c (do_test): Check stack size
+	against PTHREAD_STACK_MIN.
+
 2018-02-01  Dmitry V. Levin  <[email protected]>
 
 	* manual/contrib.texi (Palmer Dabbelt, Arjun Shankar, Florian Weimer):

stdlib/test-atexit-race-common.c

@@ -34,9 +34,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <support/xthread.h>
+#include <limits.h>
 
 const size_t kNumThreads = 1024;
 const size_t kNumHandlers = 1024;
+const size_t kStacksize =
+	0x20000 < PTHREAD_STACK_MIN ? PTHREAD_STACK_MIN : 0x20000;
 
 static void *
 threadfunc (void *unused)
@@ -60,7 +63,7 @@ do_test (void)
   /* With default 8MiB Linux stack size, creating 1024 threads can cause
      VM exhausiton on 32-bit machines.  Reduce stack size of each thread to
      128KiB for a maximum required VM size of 128MiB.  */
-  xpthread_attr_setstacksize (&attr, 128 * 1024);
+  xpthread_attr_setstacksize (&attr, kStacksize);
 
   for (i = 0; i < kNumThreads; ++i) {
     xpthread_create (&attr, threadfunc, NULL);