Add OptimizingCompilerStats to the CodeGenerator class.

Just refactoring, not yet used, but will be used by the incoming patch
series and future CodeGen specific stats.

Change-Id: I7d20489907b82678120518a77bdab9c4cc58f937
Signed-off-by: Serban Constantinescu <serban.constantinescu@linaro.org>
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 25b3ea2..348c5c8 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -510,14 +510,16 @@
 
 CodeGeneratorARM64::CodeGeneratorARM64(HGraph* graph,
                                        const Arm64InstructionSetFeatures& isa_features,
-                                       const CompilerOptions& compiler_options)
+                                       const CompilerOptions& compiler_options,
+                                       OptimizingCompilerStats* stats)
     : CodeGenerator(graph,
                     kNumberOfAllocatableRegisters,
                     kNumberOfAllocatableFPRegisters,
                     kNumberOfAllocatableRegisterPairs,
                     callee_saved_core_registers.list(),
                     callee_saved_fp_registers.list(),
-                    compiler_options),
+                    compiler_options,
+                    stats),
       block_labels_(nullptr),
       location_builder_(graph, this),
       instruction_visitor_(graph, this),