Avoid re-tagging of the index register in optimized byte array access.

runtime/vm/flow_graph_compiler.h

Index: runtime/vm/flow_graph_compiler.h
===================================================================
--- runtime/vm/flow_graph_compiler.h	(revision 18444)
+++ runtime/vm/flow_graph_compiler.h	(working copy)
@@ -210,11 +210,6 @@
   // Bail out of the flow graph compiler. Does not return to the caller.
   void Bailout(const char* reason);
 
-  void LoadDoubleOrSmiToFpu(FpuRegister result,
-                            Register reg,
-                            Register temp,
-                            Label* not_double_or_smi);
-
   // Returns 'true' if code generation for this function is complete, i.e.,
   // no fall-through to regular code is needed.
   bool TryIntrinsify();