Make X64 implementation update Store ic stubs. Remove comment that talks abo...

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
===================================================================
--- src/x64/macro-assembler-x64.cc	(revision 2535)
+++ src/x64/macro-assembler-x64.cc	(working copy)
@@ -151,6 +151,13 @@
 
 void MacroAssembler::TailCallRuntime(ExternalReference const& ext,
                                      int num_arguments) {
+  // ----------- S t a t e -------------
+  //  -- rsp[0] : return address
+  //  -- rsp[8] : argument num_arguments - 1
+  //  ...
+  //  -- rsp[8 * num_arguments] : argument 0 (receiver)
+  // -----------------------------------
+
   // TODO(1236192): Most runtime routines don't need the number of
   // arguments passed in because it is constant. At some point we
   // should remove this need and make the runtime routine entry code