[WIP] Start adding JSCallWithVarargs

src/compiler/js-operator.h

Index: src/compiler/js-operator.h
diff --git a/src/compiler/js-operator.h b/src/compiler/js-operator.h
index fc5c75da36612709635aff7238fdf7d7f33d097e..cd96563890156dfe23dc44df280a753fd75911e0 100644
--- a/src/compiler/js-operator.h
+++ b/src/compiler/js-operator.h
@@ -218,6 +218,34 @@ std::ostream& operator<<(std::ostream&, CallForwardVarargsParameters const&);
 CallForwardVarargsParameters const& CallForwardVarargsParametersOf(
     Operator const*) WARN_UNUSED_RESULT;
 
+// Defines the flags for a JavaScript call forwarding parameters. This
+// is used as parameter by JSCallVarargs operators.
+class CallVarargsParameters final {
+ public:
+  explicit CallVarargsParameters(size_t arity) : arity_(arity) {}
+
+  size_t arity() const { return arity_; }
+
+  bool operator==(CallVarargsParameters const& that) const {
+    return this->arity_ == that.arity_;
+  }
+  bool operator!=(CallVarargsParameters const& that) const {
+    return !(*this == that);
+  }
+
+ private:
+  friend size_t hash_value(CallVarargsParameters const& p) {
+    return p.arity_;
+  }
+
+  const size_t arity_;
+};
+
+std::ostream& operator<<(std::ostream&, CallVarargsParameters const&);
+
+CallVarargsParameters const& CallVarargsParametersOf(Operator const*)
+    WARN_UNUSED_RESULT;
+
 // Defines the arity and the call flags for a JavaScript function call. This is
 // used as a parameter by JSCall operators.
 class CallParameters final {
@@ -726,13 +754,14 @@ class V8_EXPORT_PRIVATE JSOperatorBuilder final
   const Operator* CreateLiteralRegExp(Handle<String> constant_pattern,
                                       int literal_flags, int literal_index);
 
-  const Operator* CallForwardVarargs(size_t arity, uint32_t start_index,
-                                     TailCallMode tail_call_mode);
   const Operator* Call(
       size_t arity, CallFrequency frequency = CallFrequency(),
       VectorSlotPair const& feedback = VectorSlotPair(),
       ConvertReceiverMode convert_mode = ConvertReceiverMode::kAny,
       TailCallMode tail_call_mode = TailCallMode::kDisallow);
+  const Operator* CallForwardVarargs(size_t arity, uint32_t start_index,
+                                     TailCallMode tail_call_mode);
+  const Operator* CallVarargs(size_t arity);
   const Operator* CallWithArrayLike(CallFrequency frequency);
   const Operator* CallWithSpread(uint32_t arity);
   const Operator* CallRuntime(Runtime::FunctionId id);