Re-apply: Initial check-in of an optimizing compiler.

The classes and the names are very much inspired by V8/Dart.
It currently only supports the RETURN_VOID dex instruction,
and there is a pretty printer to check if the building of the
graph is correct.

Change-Id: I28e125dfee86ae6ec9b3fec6aa1859523b92a893
diff --git a/compiler/dex/compiler_ir.h b/compiler/dex/compiler_ir.h
index ea8eb1c..ded8005 100644
--- a/compiler/dex/compiler_ir.h
+++ b/compiler/dex/compiler_ir.h
@@ -19,7 +19,6 @@
 
 #include <vector>
 #include <llvm/IR/Module.h>
-#include "arena_allocator.h"
 #include "compiler_enums.h"
 #include "dex/quick/mir_to_lir.h"
 #include "dex_instruction.h"
@@ -29,6 +28,7 @@
 #include "llvm/ir_builder.h"
 #include "safe_map.h"
 #include "base/timing_logger.h"
+#include "utils/arena_allocator.h"
 
 namespace art {