Implement IC for storing to dictionary case objects....

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
===================================================================
--- src/x64/macro-assembler-x64.h	(revision 4975)
+++ src/x64/macro-assembler-x64.h	(working copy)
@@ -93,16 +93,27 @@
                   Condition cc,
                   Label* branch);
 
-  // For page containing |object| mark region covering [object+offset] dirty.
-  // object is the object being stored into, value is the object being stored.
-  // If offset is zero, then the scratch register contains the array index into
-  // the elements array represented as a Smi.
-  // All registers are clobbered by the operation.
+  // For page containing |object| mark region covering [object+offset]
+  // dirty. |object| is the object being stored into, |value| is the
+  // object being stored. If |offset| is zero, then the |scratch|
+  // register contains the array index into the elements array
+  // represented as a Smi. All registers are clobbered by the
+  // operation. RecordWrite filters out smis so it does not update the
+  // write barrier if the value is a smi.
   void RecordWrite(Register object,
                    int offset,
                    Register value,
                    Register scratch);
 
+  // For page containing |object| mark region covering [address]
+  // dirty. |object| is the object being stored into, |value| is the
+  // object being stored. All registers are clobbered by the
+  // operation.  RecordWrite filters out smis so it does not update
+  // the write barrier if the value is a smi.
+  void RecordWrite(Register object,
+                   Register address,
+                   Register value);
+
   // For page containing |object| mark region covering [object+offset] dirty.
   // The value is known to not be a smi.
   // object is the object being stored into, value is the object being stored.