Add a type propagation phase after building SSA.

This ensures all phis have a type.

Change-Id: I7e4f9a16d1efb5f64c493c1351749b352c870cbd
diff --git a/compiler/Android.mk b/compiler/Android.mk
index cfce9f7..3cf7368 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -91,6 +91,7 @@
 	optimizing/register_allocator.cc \
 	optimizing/ssa_builder.cc \
 	optimizing/ssa_liveness_analysis.cc \
+	optimizing/ssa_type_propagation.cc \
 	trampolines/trampoline_compiler.cc \
 	utils/arena_allocator.cc \
 	utils/arena_bit_vector.cc \