tests: SKIP backtrace-data and backtrace-dwarf on unsupported arches.

run-backtrace-data.sh did check stderr whether the arch was unsupported
but the test didn't print that message yet. backtrace-dwarf did print
the message but was missing a check_unsupported test. Also add an explicit
check_main test for backtrace-dwarf.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
diff --git a/tests/ChangeLog b/tests/ChangeLog
index b366689..8992568 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,8 @@
+2013-12-05  Mark Wielaard  <mjw@redhat.com>
+
+	* backtrace-data.c (main): If unsupported also print to stderr.
+	* run-backtrace-dwarf.sh: Add check_unsupported and check_main.
+
 2013-12-04  Mark Wielaard  <mjw@redhat.com>
 
 	* Makefile.am (backtrace-child-biarch): Add $(EXEEXT).