Compress the StackMaps.

First step towards the compression of the StackMap (not
the DexRegisterMap). Next step will be to just use what is
needed (instead of byte -> word).

Change-Id: I4f81b2d05bf5cc508585e16fbbed1bafbc850e2e
diff --git a/runtime/Android.mk b/runtime/Android.mk
index 6588288..5548d94 100644
--- a/runtime/Android.mk
+++ b/runtime/Android.mk
@@ -151,6 +151,7 @@
   runtime_options.cc \
   signal_catcher.cc \
   stack.cc \
+  stack_map.cc \
   thread.cc \
   thread_list.cc \
   thread_pool.cc \