Revert "Introduce a class to implement optimization passes."

This reverts commit bf9cd7ba2118a75f5aa9b56241c4d5fa00dedeb8.

Change-Id: I0a483446666c9c24c45925a5fc199debdefd8b3e
diff --git a/compiler/optimizing/dead_code_elimination.cc b/compiler/optimizing/dead_code_elimination.cc
index 5518851..fe2adc7 100644
--- a/compiler/optimizing/dead_code_elimination.cc
+++ b/compiler/optimizing/dead_code_elimination.cc
@@ -20,7 +20,7 @@
 
 namespace art {
 
-void HDeadCodeElimination::Run() {
+void DeadCodeElimination::Run() {
   // Process basic blocks in post-order in the dominator tree, so that
   // a dead instruction depending on another dead instruction is
   // removed.