Pass the 'extra' parameter for X64OperandConverter::ToOperand

BUG=

Review URL: https://codereview.chromium.org/1799113003

Cr-Commit-Position: refs/heads/master@{#34750}

src/compiler/x64/code-generator-x64.cc

@@ -49,7 +49,7 @@ class X64OperandConverter : public InstructionOperandConverter {
 
   Operand ToOperand(InstructionOperand* op, int extra = 0) {
     DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
-    return SlotToOperand(AllocatedOperand::cast(op)->index());
+    return SlotToOperand(AllocatedOperand::cast(op)->index(), extra);
   }
 
   Operand SlotToOperand(int slot_index, int extra = 0) {