[PATCH] libbacktrace: Fix compile warning building testcase

[Sam Thursfield]

Hello,
I hit this compile warning running `make check` on AIX. Since -Werror is 
enabled by default here it causes a build failure.

Tested on powerpc-ibm-aix7.2.0.0

This my first patch submission for GCC, so please let me know if I need 
to do anything differently.
Thanks
Sam
>From a0d73b85afd593aafd50e454d9a86acd9f0bc489 Mon Sep 17 00:00:00 2001
From: Sam Thursfield <sam.thursfi...@codethink.co.uk>
Date: Fri, 3 Mar 2017 08:38:42 -0600
Subject: [PATCH] libbacktrace: Fix compile warning building testcase

This warning occurred when the BACKTRACE_SUPPORTED flag is undefined.

    ../../../gcc/libbacktrace/btest.c:624:1: error: 'test5' defined but not used [-Werror=unused-function]
     test5 (void)
     ^~~~~
    cc1: all warnings being treated as errors

libbacktrace/:

2017-03-03  Sam Thursfield  <sam.thursfi...@codethink.co.uk>

       * btest.c (test5): Fix compile warning when BACKTRACE_SUPPORTED isn't
       defined.
---
 libbacktrace/btest.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libbacktrace/btest.c b/libbacktrace/btest.c
index e28a3d8..bed547a 100644
--- a/libbacktrace/btest.c
+++ b/libbacktrace/btest.c
@@ -616,6 +616,7 @@ f33 (int f1line, int f2line)
   return failures;
 }
 
+#if BACKTRACE_SUPPORTED
 #if BACKTRACE_SUPPORTS_DATA
 
 int global = 1;
@@ -687,6 +688,7 @@ test5 (void)
 }
 
 #endif /* BACKTRACE_SUPPORTS_DATA  */
+#endif /* BACKTRACE_SUPPORTED */
 
 static void
 error_callback_create (void *data ATTRIBUTE_UNUSED, const char *msg,
-- 
2.2.2