Darwin doesn't have pthread_barrier, at least up to Darwin18

so don't try to do tests with it.

2018-08-16  Iain Sandoe <iain@sandoe.co.uk>

gcc/testsuite/
	* c-c++-common/asan/pointer-subtract-3.c: Skip for Darwin.
	* c-c++-common/asan/pointer-subtract-4.c: Likewise.
	* g++.dg/torture/pr44295.C : Likewise.

From-SVN: r263585

gcc/testsuite/ChangeLog

 2018-08-16  Iain Sandoe <iain@sandoe.co.uk>
 
+	* c-c++-common/asan/pointer-subtract-3.c: Skip for Darwin.
+	* c-c++-common/asan/pointer-subtract-4.c: Likewise.
+	* g++.dg/torture/pr44295.C : Likewise.
+
+2018-08-16  Iain Sandoe <iain@sandoe.co.uk>
+
 	PR testsuite/78544
 	* gcc.dg/tree-prof/section-attr-1.c: Add Darwin-specific section
 	attributes and matching.

gcc/testsuite/c-c++-common/asan/pointer-subtract-3.c

 /* { dg-do run { target pthread_h } } */
+/* { dg-skip-if "no pthread_barrier" { *-*-darwin* } } */
 /* { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=2:halt_on_error=1" } */
 /* { dg-options "-fsanitize=address,pointer-subtract" } */
 /* { dg-additional-options "-pthread" { target pthread } } */

gcc/testsuite/c-c++-common/asan/pointer-subtract-4.c

 /* { dg-do run { target pthread_h } } */
+/* { dg-skip-if "no pthread_barrier" { *-*-darwin* } } */
 /* { dg-shouldfail "asan" } */
 /* { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=2:halt_on_error=1" } */
 /* { dg-options "-fsanitize=address,pointer-subtract" } */

gcc/testsuite/g++.dg/torture/pr44295.C

 /* { dg-do compile } */
 /* { dg-additional-options "-Wno-return-type" } */
+/* { dg-skip-if "no pthread_barrier" { *-*-darwin* } } */
 
 extern "C" {
   typedef __SIZE_TYPE__ size_t;