[testsuite] VLA test uses alloca

[Nathan Sidwell]

gcc.dg/vla-24.c uses alloca.   Marked accordingly and committed as obvious.

nathan

2015-12-04  Nathan Sidwell  <nat...@acm.org>

	* gcc.dg/vla-24.c: Requires alloca.

Index: testsuite/gcc.dg/vla-24.c
===================================================================
--- testsuite/gcc.dg/vla-24.c	(revision 231302)
+++ testsuite/gcc.dg/vla-24.c	(working copy)
@@ -2,6 +2,7 @@
 
 /* { dg-do run } */
 /* { dg-options "-std=gnu99" } */
+/* { dg-require-effective-target alloca } */
 
 extern void abort (void);