Add microblaze support

Signed-off-by: Spenser Gilliland <spenser@gillilanding.com>

Index: libsigsegv-2.10/m4/stack-direction.m4
===================================================================
--- libsigsegv-2.10.orig/m4/stack-direction.m4	2014-01-08 10:15:43.149509801 -0600
+++ libsigsegv-2.10/m4/stack-direction.m4	2014-01-08 10:16:57.249511153 -0600
@@ -32,6 +32,7 @@
       m68* | \
       m88k | \
       mcore | \
+      microblaze | \
       mips* | \
       mmix | \
       mn10200 | \