More constification.


git-svn-id: svn://svn.valgrind.org/vex/trunk@3040 8f6e269a-dfd6-0310-a8e1-e2731360e62c
diff --git a/priv/host_arm64_isel.c b/priv/host_arm64_isel.c
index 5759994..06ba672 100644
--- a/priv/host_arm64_isel.c
+++ b/priv/host_arm64_isel.c
@@ -3864,7 +3864,7 @@
 
 /* Translate an entire SB to arm64 code. */
 
-HInstrArray* iselSB_ARM64 ( IRSB* bb,
+HInstrArray* iselSB_ARM64 ( const IRSB* bb,
                             VexArch      arch_host,
                             const VexArchInfo* archinfo_host,
                             const VexAbiInfo*  vbi/*UNUSED*/,