Support fast case for-in in Crankshaft.

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
diff --git a/src/arm/macro-assembler-arm.h b/src/arm/macro-assembler-arm.h
index fad698ef072d29c935663c09deda57e2b117c8af..47afa93a6e0e637e31255ea4c4fe43ceea5358e5 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -1259,6 +1259,10 @@ class MacroAssembler: public Assembler {
   void EnterFrame(StackFrame::Type type);
   void LeaveFrame(StackFrame::Type type);
 
+  // Expects object in r0 and returns map with validated enum cache
+  // in r0.  Assumes that any other register can be used as a scratch.
+  void CheckEnumCache(Register null_value, Label* call_runtime);
+
  private:
   void CallCFunctionHelper(Register function,
                            int num_reg_arguments,