[turbofan] Introduce CallDescriptorOf helper for safety.

src/compiler/linkage.cc

 // Copyright 2014 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/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/frame.h"
 #include "src/compiler/linkage.h"
@@ skipping 70 matching lines @@
   if (ReturnCount() != other->ReturnCount()) return false;
   for (size_t i = 0; i < ReturnCount(); ++i) {
     if (GetReturnLocation(i) != other->GetReturnLocation(i)) return false;
   }
   return true;
 }
 
 
 bool CallDescriptor::CanTailCall(const Node* node,
                                  int* stack_param_delta) const {
-  CallDescriptor const* other = OpParameter<CallDescriptor const*>(node);
+  CallDescriptor const* other = CallDescriptorOf(node->op());
   size_t current_input = 0;
   size_t other_input = 0;
   *stack_param_delta = 0;
   bool more_other = true;
   bool more_this = true;
   while (more_other || more_this) {
     if (other_input < other->InputCount()) {
       if (!other->GetInputLocation(other_input).IsRegister()) {
         (*stack_param_delta)--;
       }
     } else {
       more_other = false;
     }
     if (current_input < InputCount()) {
       if (!GetInputLocation(current_input).IsRegister()) {
         (*stack_param_delta)++;
       }
     } else {
       more_this = false;
     }
     ++current_input;
     ++other_input;
   }
-  return HasSameReturnLocationsAs(OpParameter<CallDescriptor const*>(node));
+  return HasSameReturnLocationsAs(CallDescriptorOf(node->op()));
 }
 
 
 CallDescriptor* Linkage::ComputeIncoming(Zone* zone, CompilationInfo* info) {
   DCHECK(!info->IsStub());
   if (!info->closure().is_null()) {
     // If we are compiling a JS function, use a JS call descriptor,
     // plus the receiver.
     SharedFunctionInfo* shared = info->closure()->shared();
     return GetJSCallDescriptor(zone, info->is_osr(),
@@ skipping 362 matching lines @@
   } else {
     DCHECK(loc == regloc(kContextRegister));
     return LinkageLocation::ForCalleeFrameSlot(Frame::kContextSlot);
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8