Move code around and address growable_array comment.

- Move SideEffectsAnalysis to its own file.
- Move most of gvn.h to gvn.cc.
- Don't call Resize in GrowableArray constructor, but just set num_used
  directly.

Change-Id: I1f1291207945d678d3c99cc0ec1ec155bcae82f6
diff --git a/compiler/Android.mk b/compiler/Android.mk
index f2f4550..bf4572a 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -107,6 +107,7 @@
 	optimizing/parallel_move_resolver.cc \
 	optimizing/prepare_for_register_allocation.cc \
 	optimizing/register_allocator.cc \
+	optimizing/side_effects_analysis.cc \
 	optimizing/ssa_builder.cc \
 	optimizing/ssa_liveness_analysis.cc \
 	optimizing/ssa_phi_elimination.cc \