Make sure malloc is linked into gdb.cp/oranking.cc.

On some platforms, e.g., arm-eabi-none, we need to make certain that
malloc is linked into the program because the test suite uses function
calls requiring malloc:

(gdb) p foo101("abc")
evaluation of this expression requires the program to have a function "malloc".

gdb/testsuite/ChangeLog

	* gdb.cp/oranking.cc (dummy): New function to grab malloc.
	(main): Call it.

1 files changed, 17 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.cp/oranking.cc b/gdb/testsuite/gdb.cp/oranking.cc
index bd2f51bb05..135761016c 100644
--- a/gdb/testsuite/gdb.cp/oranking.cc
+++ b/gdb/testsuite/gdb.cp/oranking.cc
@@ -1,3 +1,18 @@
+#include <cstdlib>
+
+/* Make sure `malloc' is linked into the program.  If we don't, tests
+   in the accompanying expect file may fail:
+
+   evaluation of this expression requires the program to have a function
+   "malloc".  */
+
+void
+dummy ()
+{
+  void *p = malloc (16);
+
+  free (p);
+}
 
 /* 1. A standard covnersion sequence is better than a user-defined sequence
       which is better than an elipses conversion sequence.  */
@@ -165,6 +180,8 @@ test15 ()
 }
 
 int main() {
+  dummy ();
+
   B b;
   foo0(b);
   foo1(b);