86658.cc: Use dg-options to define _GLIBCXX_DEBUG.

2018-08-18  François Dumont  <fdumont@gcc.gnu.org>

	* testsuite/25_algorithms/copy/86658.cc: Use dg-options to define
	_GLIBCXX_DEBUG.

From-SVN: r263647

libstdc++-v3/ChangeLog

+2018-08-18  François Dumont  <fdumont@gcc.gnu.org>
+
+	* testsuite/25_algorithms/copy/86658.cc: Use dg-options to define
+	_GLIBCXX_DEBUG.
+
 2018-08-17  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/86963

libstdc++-v3/testsuite/25_algorithms/copy/86658.cc

@@ -15,9 +15,9 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
+// { dg-options "-D_GLIBCXX_DEBUG" }
 // { dg-do run }
 
-#define _GLIBCXX_DEBUG
 #include <algorithm>
 #include <vector>