avoid includes

From-SVN: r47064

gcc/testsuite/g++.old-deja/g++.other/null2.C

 // Based on a testcase by Eric Dumazet <Eric.Dumazet@COSMOSBAY.COM>
 
-#include <cstdlib>
+extern "C" void abort ();
 
 const char * const foo = ""; // foo is not NULL
 
@@ -8,5 +8,5 @@ int main() {
   if ((foo == 0) ? 0 : foo)  // so this should evaluate to `foo'
     return 0;
   else
-    std::abort();
+    abort();
 }