Revert "Introduce a class to implement optimization passes."

This reverts commit bf9cd7ba2118a75f5aa9b56241c4d5fa00dedeb8.

Change-Id: I0a483446666c9c24c45925a5fc199debdefd8b3e
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index 7c9a69b..af43a3c 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -141,7 +141,7 @@
   compiler/oat_test.cc \
   compiler/optimizing/codegen_test.cc \
   compiler/optimizing/dead_code_elimination_test.cc \
-  compiler/optimizing/constant_folding_test.cc \
+  compiler/optimizing/constant_propagation_test.cc \
   compiler/optimizing/dominator_test.cc \
   compiler/optimizing/find_loops_test.cc \
   compiler/optimizing/graph_checker_test.cc \