[v3] fix PR 54297 - segfaults with std::async

[Jonathan Wakely]

       * testsuite/30_threads/async/54297.cc: Add dg-require-nanosleep.

Fixed on trunk and 4.7 branch.


--- a/libstdc++-v3/testsuite/30_threads/async/54297.cc
+++ b/libstdc++-v3/testsuite/30_threads/async/54297.cc
@@ -5,6 +5,7 @@
 // { dg-require-cstdint "" }
 // { dg-require-gthreads "" }
 // { dg-require-atomic-builtins "" }
+// { dg-require-nanosleep "" }

 // Copyright (C) 2012 Free Software Foundation, Inc.
 //