A64: Improve the deoptimization helpers to generate fewer instructions.

src/a64/lithium-codegen-a64.h

Index: src/a64/lithium-codegen-a64.h
diff --git a/src/a64/lithium-codegen-a64.h b/src/a64/lithium-codegen-a64.h
index 006165157f46740fd44428a3a4322eb64c56ad7b..0889fb2a24940674e0073d9f63c2ac1477f81480 100644
--- a/src/a64/lithium-codegen-a64.h
+++ b/src/a64/lithium-codegen-a64.h
@@ -221,6 +221,18 @@ class LCodeGen: public LCodeGenBase {
   Deoptimizer::BailoutType DeoptimizeHeader(
       LEnvironment* environment,
       Deoptimizer::BailoutType* override_bailout_type);
+  void DeoptimizeBranch(LEnvironment* environment,
+                        Deoptimizer::BailoutType bailout_type,
+                        BranchType branch_type,
+                        Register reg = NoReg,
+                        int bit = -1);
+  void DeoptimizeBranch(LEnvironment* environment,
+                        BranchType branch_type,
+                        Register reg = NoReg,
+                        int bit = -1) {
+    Deoptimizer::BailoutType bailout_type = DeoptimizeHeader(environment, NULL);
+    DeoptimizeBranch(environment, bailout_type, branch_type, reg, bit);
+  }
   void Deoptimize(LEnvironment* environment);
   void Deoptimize(LEnvironment* environment,
                   Deoptimizer::BailoutType bailout_type);