Fix the GC branch so it compiles and runs on 64 bit.

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
===================================================================
--- src/x64/full-codegen-x64.cc	(revision 7889)
+++ src/x64/full-codegen-x64.cc	(working copy)
@@ -693,11 +693,18 @@
           __ movq(ContextOperand(rsi, slot->index()), kScratchRegister);
           // No write barrier since the hole value is in old space.
         } else if (function != NULL) {
+          // We know that we have written a function, which is not a smi.
           VisitForAccumulatorValue(function);
           __ movq(ContextOperand(rsi, slot->index()), result_register());
           int offset = Context::SlotOffset(slot->index());
           __ movq(rbx, rsi);
-          __ RecordWrite(rbx, offset, result_register(), rcx, kDontSaveFPRegs);
+          __ RecordWrite(rbx,
+                         offset,
+                         result_register(),
+                         rcx,
+                         kDontSaveFPRegs,
+                         EMIT_REMEMBERED_SET,
+                         OMIT_SMI_CHECK);
         }
         break;
 
@@ -1846,7 +1853,7 @@
         __ movq(ContextOperand(rcx, slot->index()), rax);
         int offset = Context::SlotOffset(slot->index());
         __ movq(rdx, rax);  // Preserve the stored value in eax.
-        __ RecordWrite(rcx, offset, rdx, rbx);
+        __ RecordWrite(rcx, offset, rdx, rbx, kDontSaveFPRegs);
         break;
       }
       case Slot::LOOKUP:
@@ -3139,8 +3146,8 @@
   __ InNewSpace(elements, temp, equal, &new_space);
 
   __ movq(object, elements);
-  __ RecordWriteHelper(object, index_1, temp);
-  __ RecordWriteHelper(elements, index_2, temp);
+  __ RecordWriteHelper(object, index_1, temp, kDontSaveFPRegs);
+  __ RecordWriteHelper(elements, index_2, temp, kDontSaveFPRegs);
 
   __ bind(&new_space);
   // We are done. Drop elements from the stack, and return undefined.