[crankshaft] Support ES6 tail call elimination.

src/crankshaft/arm/lithium-codegen-arm.h

Index: src/crankshaft/arm/lithium-codegen-arm.h
diff --git a/src/crankshaft/arm/lithium-codegen-arm.h b/src/crankshaft/arm/lithium-codegen-arm.h
index 67925ccdf63c0c5ac6aef4d3c8d026733c19e6c3..8bbacc3c5830cbf29ab42ff95c915a3e0388d937 100644
--- a/src/crankshaft/arm/lithium-codegen-arm.h
+++ b/src/crankshaft/arm/lithium-codegen-arm.h
@@ -218,11 +218,14 @@ class LCodeGen: public LCodeGenBase {
                                LInstruction* instr,
                                LOperand* context);
 
+  void PrepareForTailCall(const ParameterCount& actual, Register scratch1,
+                          Register scratch2, Register scratch3);
+
   // Generate a direct call to a known function.  Expects the function
   // to be in r1.
   void CallKnownFunction(Handle<JSFunction> function,
                          int formal_parameter_count, int arity,
-                         LInstruction* instr);
+                         bool is_tail_call, LInstruction* instr);
 
   void RecordSafepointWithLazyDeopt(LInstruction* instr,
                                     SafepointMode safepoint_mode);