[Interpreter] Adds support for rest parameters to interpreter.

test/cctest/interpreter/test-interpreter.cc

 // Copyright 2015 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/v8.h"
 
 #include "src/execution.h"
 #include "src/handles.h"
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/interpreter.h"
@@ skipping 2279 matching lines @@
       std::make_pair("function f(a, b, c, d) {"
                      "'use strict'; return arguments[2]; }",
                      2),
       // Check arguments are mapped in sloppy mode and unmapped in strict.
       std::make_pair("function f(a, b, c, d) {"
                      "  c = b; return arguments[2]; }",
                      1),
       std::make_pair("function f(a, b, c, d) {"
                      "  'use strict'; c = b; return arguments[2]; }",
                      2),
+      // check rest parameters
+      std::make_pair("function f(...restArray) { return restArray[0]; }", 0),
+      std::make_pair("function f(a, ...restArray) { return restArray[0]; }", 1),
+      std::make_pair("function f(a, ...restArray) { return arguments[0]; }", 0),
+      std::make_pair("function f(a, ...restArray) { return arguments[1]; }", 1),
+      std::make_pair("function f(a, ...restArray) { return restArray[1]; }", 2),
+      std::make_pair("function f(a, ...arguments) { return arguments[0]; }", 1),
+      std::make_pair("function f(a, b, ...restArray) { return restArray[0]; }",
+                     2),
   };
 
   // Test passing no arguments.
   for (size_t i = 0; i < arraysize(create_args); i++) {
     InterpreterTester tester(handles.main_isolate(), create_args[i].first);
     auto callable = tester.GetCallable<>();
     Handle<Object> return_val = callable().ToHandleChecked();
     CHECK(return_val.is_identical_to(factory->undefined_value()));
   }
 
@@ skipping 1520 matching lines @@
     Handle<i::Object> return_value = callable().ToHandleChecked();
     CHECK(return_value->SameValue(*do_expr[i].second));
   }
 
   FLAG_harmony_do_expressions = old_flag;
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8