[runtime] Optimize and unify rest parameters.

src/compiler/js-operator.cc

Index: src/compiler/js-operator.cc
diff --git a/src/compiler/js-operator.cc b/src/compiler/js-operator.cc
index 46282a1addd0a7a95f89fa13d7d08b8fa31a9060..64a791d496576a53a227f2ff47bc176e4eeed170 100644
--- a/src/compiler/js-operator.cc
+++ b/src/compiler/js-operator.cc
@@ -350,32 +350,9 @@ const StoreGlobalParameters& StoreGlobalParametersOf(const Operator* op) {
 }
 
 
-bool operator==(CreateArgumentsParameters const& lhs,
-                CreateArgumentsParameters const& rhs) {
-  return lhs.type() == rhs.type() && lhs.start_index() == rhs.start_index();
-}
-
-
-bool operator!=(CreateArgumentsParameters const& lhs,
-                CreateArgumentsParameters const& rhs) {
-  return !(lhs == rhs);
-}
-
-
-size_t hash_value(CreateArgumentsParameters const& p) {
-  return base::hash_combine(p.type(), p.start_index());
-}
-
-
-std::ostream& operator<<(std::ostream& os, CreateArgumentsParameters const& p) {
-  return os << p.type() << ", " << p.start_index();
-}
-
-
-const CreateArgumentsParameters& CreateArgumentsParametersOf(
-    const Operator* op) {
+CreateArgumentsType const& CreateArgumentsTypeOf(const Operator* op) {
   DCHECK_EQ(IrOpcode::kJSCreateArguments, op->opcode());
-  return OpParameter<CreateArgumentsParameters>(op);
+  return OpParameter<CreateArgumentsType>(op);
 }
 
 
@@ -888,15 +865,12 @@ const Operator* JSOperatorBuilder::LoadDynamic(const Handle<String>& name,
 }
 
 
-const Operator* JSOperatorBuilder::CreateArguments(
-    CreateArgumentsParameters::Type type, int start_index) {
-  DCHECK_IMPLIES(start_index, type == CreateArgumentsParameters::kRestArray);
-  CreateArgumentsParameters parameters(type, start_index);
-  return new (zone()) Operator1<CreateArgumentsParameters>(  // --
-      IrOpcode::kJSCreateArguments, Operator::kNoThrow,      // opcode
-      "JSCreateArguments",                                   // name
-      1, 1, 1, 1, 1, 0,                                      // counts
-      parameters);                                           // parameter
+const Operator* JSOperatorBuilder::CreateArguments(CreateArgumentsType type) {
+  return new (zone()) Operator1<CreateArgumentsType>(    // --
+      IrOpcode::kJSCreateArguments, Operator::kNoThrow,  // opcode
+      "JSCreateArguments",                               // name
+      1, 1, 1, 1, 1, 0,                                  // counts
+      type);                                             // parameter
 }