[turbofan] Introduce CallDescriptorOf helper for safety.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index a917328650a45af6e39bc1b3033e3ec2cad893b1..cfa4536851693d289ec924b22098cd6e144c0fc0 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -1451,7 +1451,7 @@ void InstructionSelector::VisitIfException(Node* node) {
   OperandGenerator g(this);
   Node* call = node->InputAt(1);
   DCHECK_EQ(IrOpcode::kCall, call->opcode());
-  const CallDescriptor* descriptor = OpParameter<const CallDescriptor*>(call);
+  const CallDescriptor* descriptor = CallDescriptorOf(call->op());
   Emit(kArchNop,
        g.DefineAsLocation(node, descriptor->GetReturnLocation(0),
                           descriptor->GetReturnType(0).representation()));
@@ -1523,7 +1523,7 @@ void InstructionSelector::VisitConstant(Node* node) {
 
 void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
   OperandGenerator g(this);
-  const CallDescriptor* descriptor = OpParameter<const CallDescriptor*>(node);
+  const CallDescriptor* descriptor = CallDescriptorOf(node->op());
 
   FrameStateDescriptor* frame_state_descriptor = nullptr;
   if (descriptor->NeedsFrameState()) {
@@ -1591,7 +1591,7 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
 
 void InstructionSelector::VisitTailCall(Node* node) {
   OperandGenerator g(this);
-  CallDescriptor const* descriptor = OpParameter<CallDescriptor const*>(node);
+  CallDescriptor const* descriptor = CallDescriptorOf(node->op());
   DCHECK_NE(0, descriptor->flags() & CallDescriptor::kSupportsTailCalls);
   DCHECK_EQ(0, descriptor->flags() & CallDescriptor::kPatchableCallSite);
   DCHECK_EQ(0, descriptor->flags() & CallDescriptor::kNeedsNopAfterCall);