More code generation for the optimizing compiler.

- Add HReturn instruction
- Generate code for locals/if/return
- Setup infrastructure for register allocation. Currently
  emulate a stack.

Change-Id: Ib28c2dba80f6c526177ed9a7b09c0689ac8122fb
diff --git a/compiler/optimizing/optimizing_unit_test.h b/compiler/optimizing/optimizing_unit_test.h
index bf13a41..67c4850 100644
--- a/compiler/optimizing/optimizing_unit_test.h
+++ b/compiler/optimizing/optimizing_unit_test.h
@@ -26,4 +26,7 @@
 #define ONE_REGISTER_CODE_ITEM(...)                                        \
     { 1, 0, 0, 0, 0, 0, NUM_INSTRUCTIONS(__VA_ARGS__), 0, __VA_ARGS__ }
 
+#define TWO_REGISTERS_CODE_ITEM(...)                                       \
+    { 2, 0, 0, 0, 0, 0, NUM_INSTRUCTIONS(__VA_ARGS__), 0, __VA_ARGS__ }
+
 #endif  // ART_COMPILER_OPTIMIZING_OPTIMIZING_UNIT_TEST_H_