Add two phi pruning phases.

Change-Id: Ic4f05e3df96970d78a6938b27cdf9b58ef3849b9
diff --git a/compiler/Android.mk b/compiler/Android.mk
index b469946..98a4c2f 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -95,6 +95,7 @@
 	optimizing/ssa_builder.cc \
 	optimizing/ssa_liveness_analysis.cc \
 	optimizing/ssa_type_propagation.cc \
+	optimizing/ssa_phi_elimination.cc \
 	trampolines/trampoline_compiler.cc \
 	utils/arena_allocator.cc \
 	utils/arena_bit_vector.cc \