[turbofan] Minor code cleanup for builtin inlining

src/compiler/js-typed-lowering.cc

Index: src/compiler/js-typed-lowering.cc
diff --git a/src/compiler/js-typed-lowering.cc b/src/compiler/js-typed-lowering.cc
index ed8f3b0dae4afa3f5db2af01cef9c10f2d79852d..7f50ac8b7f7b55734c7a9b7e38a761a0a79aaac8 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -1542,16 +1542,18 @@ void ReduceBuiltin(Isolate* isolate, JSGraph* jsgraph, Node* node,
   const int argc = arity + BuiltinArguments::kNumExtraArgsWithReceiver;
   Node* argc_node = jsgraph->Int32Constant(argc);
 
-  node->InsertInput(zone, arity + 2, argc_node);
-  node->InsertInput(zone, arity + 3, target);
-  node->InsertInput(zone, arity + 4, new_target);
+  static const int kStubAndReceiver = 2;
+  int cursor = arity + kStubAndReceiver;
+  node->InsertInput(zone, cursor++, argc_node);
+  node->InsertInput(zone, cursor++, target);
+  node->InsertInput(zone, cursor++, new_target);
 
   Address entry = Builtins::CppEntryOf(builtin_index);
   ExternalReference entry_ref(ExternalReference(entry, isolate));
   Node* entry_node = jsgraph->ExternalConstant(entry_ref);
 
-  node->InsertInput(zone, arity + 5, entry_node);
-  node->InsertInput(zone, arity + 6, argc_node);
+  node->InsertInput(zone, cursor++, entry_node);
+  node->InsertInput(zone, cursor++, argc_node);
 
   static const int kReturnCount = 1;
   const char* debug_name = Builtins::name(builtin_index);
@@ -1562,6 +1564,12 @@ void ReduceBuiltin(Isolate* isolate, JSGraph* jsgraph, Node* node,
   NodeProperties::ChangeOp(node, jsgraph->common()->Call(desc));
 }
 
+bool NeedsArgumentAdaptorFrame(Handle<SharedFunctionInfo> shared, int arity) {
+  static const int sentinel = SharedFunctionInfo::kDontAdaptArgumentsSentinel;
+  const int num_decl_parms = shared->internal_formal_parameter_count();
+  return (num_decl_parms != arity && num_decl_parms != sentinel);
+}
+
 }  // namespace
 
 Reduction JSTypedLowering::ReduceJSCallConstruct(Node* node) {
@@ -1587,9 +1595,7 @@ Reduction JSTypedLowering::ReduceJSCallConstruct(Node* node) {
     CallDescriptor::Flags flags = CallDescriptor::kNeedsFrameState;
 
     if (is_builtin && Builtins::HasCppImplementation(builtin_index) &&
-        (shared->internal_formal_parameter_count() == arity ||
-         shared->internal_formal_parameter_count() ==
-             SharedFunctionInfo::kDontAdaptArgumentsSentinel)) {
+        !NeedsArgumentAdaptorFrame(shared, arity)) {
       // Patch {node} to a direct CEntryStub call.
 
       // Load the context from the {target}.
@@ -1702,14 +1708,10 @@ Reduction JSTypedLowering::ReduceJSCallFunction(Node* node) {
     Node* new_target = jsgraph()->UndefinedConstant();
     Node* argument_count = jsgraph()->Int32Constant(arity);
     if (is_builtin && Builtins::HasCppImplementation(builtin_index) &&
-        (shared->internal_formal_parameter_count() == arity ||
-         shared->internal_formal_parameter_count() ==
-             SharedFunctionInfo::kDontAdaptArgumentsSentinel)) {
+        !NeedsArgumentAdaptorFrame(shared, arity)) {
       // Patch {node} to a direct CEntryStub call.
       ReduceBuiltin(isolate(), jsgraph(), node, builtin_index, arity, flags);
-    } else if (shared->internal_formal_parameter_count() == arity ||
-               shared->internal_formal_parameter_count() ==
-                   SharedFunctionInfo::kDontAdaptArgumentsSentinel) {
+    } else if (!NeedsArgumentAdaptorFrame(shared, arity)) {
       // Patch {node} to a direct call.
       node->InsertInput(graph()->zone(), arity + 2, new_target);
       node->InsertInput(graph()->zone(), arity + 3, argument_count);