[turbofan] Introduce CallDescriptorOf helper for safety.

src/compiler/common-operator.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/compiler/common-operator.h"
 
 #include "src/assembler.h"
 #include "src/base/lazy-instance.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
@@ skipping 80 matching lines @@
 std::ostream& operator<<(std::ostream& os, SelectParameters const& p) {
   return os << p.representation() << "|" << p.hint();
 }
 
 
 SelectParameters const& SelectParametersOf(const Operator* const op) {
   DCHECK_EQ(IrOpcode::kSelect, op->opcode());
   return OpParameter<SelectParameters>(op);
 }
 
+CallDescriptor const* CallDescriptorOf(const Operator* const op) {
+  DCHECK(op->opcode() == IrOpcode::kCall ||
+         op->opcode() == IrOpcode::kTailCall);
+  return OpParameter<CallDescriptor const*>(op);
+}
 
 size_t ProjectionIndexOf(const Operator* const op) {
   DCHECK_EQ(IrOpcode::kProjection, op->opcode());
   return OpParameter<size_t>(op);
 }
 
 
 MachineRepresentation PhiRepresentationOf(const Operator* const op) {
   DCHECK_EQ(IrOpcode::kPhi, op->opcode());
   return OpParameter<MachineRepresentation>(op);
@@ skipping 788 matching lines @@
 CommonOperatorBuilder::CreateFrameStateFunctionInfo(
     FrameStateType type, int parameter_count, int local_count,
     Handle<SharedFunctionInfo> shared_info) {
   return new (zone()->New(sizeof(FrameStateFunctionInfo)))
       FrameStateFunctionInfo(type, parameter_count, local_count, shared_info);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8