Revert "Revert "Deoptimization-based bce.""

This reverts commit 0ba627337274ccfb8c9cb9bf23fffb1e1b9d1430.

Change-Id: I1ca10d15bbb49897a0cf541ab160431ec180a006
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index a380b6a..4b8f087 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -182,6 +182,10 @@
   void GenerateExplicitNullCheck(HNullCheck* instruction);
   void PushOntoFPStack(Location source, uint32_t temp_offset,
                        uint32_t stack_adjustment, bool is_float);
+  void GenerateTestAndBranch(HInstruction* instruction,
+                             Label* true_target,
+                             Label* false_target,
+                             Label* always_true_target);
 
   X86_64Assembler* const assembler_;
   CodeGeneratorX86_64* const codegen_;