[turbofan] cleanup InstructionOperand a little

src/compiler/ia32/code-generator-ia32.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/ia32/assembler-ia32.h"
@@ skipping 29 matching lines @@
   Operand ToOperand(InstructionOperand* op, int extra = 0) {
     if (op->IsRegister()) {
       DCHECK(extra == 0);
       return Operand(ToRegister(op));
     } else if (op->IsDoubleRegister()) {
       DCHECK(extra == 0);
       return Operand(ToDoubleRegister(op));
     }
     DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
     // The linkage computes where all spill slots are located.
-    FrameOffset offset = linkage()->GetFrameOffset(op->index(), frame(), extra);
+    FrameOffset offset = linkage()->GetFrameOffset(
+        AllocatedOperand::cast(op)->index(), frame(), extra);
     return Operand(offset.from_stack_pointer() ? esp : ebp, offset.offset());
   }
 
   Operand HighOperand(InstructionOperand* op) {
     DCHECK(op->IsDoubleStackSlot());
     return ToOperand(op, kPointerSize);
   }
 
   Immediate ToImmediate(InstructionOperand* operand) {
     Constant constant = ToConstant(operand);
@@ skipping 1362 matching lines @@
     }
   }
   MarkLazyDeoptSite();
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8