Added pass framework

The patch adds a Middle-End pass system and normalizes the current
 passes into the pass framework.

Passes have:
 - A start, work, and end functions.
 - A gate to determine to apply the pass.
 - Can provide a CFG dump folder.

mir_dataflow.cc, mir_graph.cc, mir_optimization.cc, ssa_transformation.cc:
 - Changed due to moving code into bb_optimizations.cc.
 - Moved certain functions from private to public due to needed from the passes.

pass.cc, pass.h:
 - Pass base class

pass_driver.cc, pass_driver.h:
 - The pass driver implementation.

frontend.cc:
 - Replace the function calls to the passes with the pass driver.

Change-Id: I88cd82efbf6499df9e6c7f135d7e294dd724a079
Signed-off-by: Jean Christophe Beyler <jean.christophe.beyler@intel.com>
diff --git a/compiler/dex/frontend.cc b/compiler/dex/frontend.cc
index adfbf2f..f5bb85a 100644
--- a/compiler/dex/frontend.cc
+++ b/compiler/dex/frontend.cc
@@ -21,6 +21,7 @@
 #include "dataflow_iterator-inl.h"
 #include "leb128.h"
 #include "mirror/object.h"
+#include "pass_driver.h"
 #include "runtime.h"
 #include "backend.h"
 #include "base/logging.h"
@@ -251,36 +252,9 @@
   }
 #endif
 
-  /* Do a code layout pass */
-  cu.NewTimingSplit("MIROpt:CodeLayout");
-  cu.mir_graph->CodeLayout();
-
-  /* Perform SSA transformation for the whole method */
-  cu.NewTimingSplit("MIROpt:SSATransform");
-  cu.mir_graph->SSATransformation();
-
-  /* Do constant propagation */
-  cu.NewTimingSplit("MIROpt:ConstantProp");
-  cu.mir_graph->PropagateConstants();
-
-  cu.NewTimingSplit("MIROpt:InitRegLoc");
-  cu.mir_graph->InitRegLocations();
-
-  /* Count uses */
-  cu.NewTimingSplit("MIROpt:UseCount");
-  cu.mir_graph->MethodUseCount();
-
-  /* Perform null check elimination and type inference*/
-  cu.NewTimingSplit("MIROpt:NCE_TypeInference");
-  cu.mir_graph->NullCheckEliminationAndTypeInference();
-
-  /* Combine basic blocks where possible */
-  cu.NewTimingSplit("MIROpt:BBCombine");
-  cu.mir_graph->BasicBlockCombine();
-
-  /* Do some basic block optimizations */
-  cu.NewTimingSplit("MIROpt:BBOpt");
-  cu.mir_graph->BasicBlockOptimization();
+  /* Create the pass driver and launch it */
+  PassDriver driver(&cu);
+  driver.Launch();
 
   if (cu.enable_debug & (1 << kDebugDumpCheckStats)) {
     cu.mir_graph->DumpCheckStats();