Add stack canaries / strcpy tests.

Add a test to ensure that stack canaries are working
correctly. Since stack canaries aren't normally generated
on non-string functions, we have to enable stack-protector-all.

Add a test to ensure that an out of bounds strcpy generates
a runtime failure.

Change-Id: Id0d3e59fc4b9602da019e4d35c5c653e1a57fae4
diff --git a/tests/Android.mk b/tests/Android.mk
index a50232e..635c021 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -47,7 +47,7 @@
 # -----------------------------------------------------------------------------
 
 test_c_flags = \
-    -fstack-protector \
+    -fstack-protector-all \
     -g \
     -Wall -Wextra \
     -Werror \