[patch, testsuite] Fix fragile case nsdmi-union5

[Joey Ye]

Resulting from discussion here:
http://gcc.gnu.org/ml/gcc/2014-04/msg00125.html

ChangeLog:
        * g++.dg/cpp0x/nsdmi-union5.C: Change to runtime test.

Index: gcc/testsuite/g++.dg/cpp0x/nsdmi-union5.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/nsdmi-union5.C   (revision 209462)
+++ gcc/testsuite/g++.dg/cpp0x/nsdmi-union5.C   (working copy)
@@ -1,6 +1,5 @@
 // PR c++/58701
-// { dg-require-effective-target c++11 }
-// { dg-final { scan-assembler "7" } }
+// { dg-do run { target c++11 } }
 
 static union
 {
@@ -9,3 +8,10 @@
     int i = 7;
   };
 };
+
+extern "C" void abort(void);
+int main()
+{
+  if (i != 7) abort();
+  return 0;
+}