Implement .forEach() on typed arrays

src/runtime/runtime-typedarray.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/v8.h"
 
 #include "src/arguments.h"
 #include "src/runtime/runtime.h"
 #include "src/runtime/runtime-utils.h"
 
@@ skipping 482 matching lines @@
 
 
 RUNTIME_FUNCTION(Runtime_TypedArrayMaxSizeInHeap) {
   DCHECK(args.length() == 0);
   DCHECK_OBJECT_SIZE(FLAG_typed_array_max_size_in_heap +
                      FixedTypedArrayBase::kDataOffset);
   return Smi::FromInt(FLAG_typed_array_max_size_in_heap);
 }
 
 
+RUNTIME_FUNCTION(Runtime_IsTypedArray) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  return isolate->heap()->ToBoolean(args[0]->IsJSTypedArray());
+}
+
+
 RUNTIME_FUNCTION(Runtime_DataViewInitialize) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(JSDataView, holder, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, buffer, 1);
   CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_offset, 2);
   CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_length, 3);
 
   DCHECK(holder->GetInternalFieldCount() ==
          v8::ArrayBufferView::kInternalFieldCount);
@@ skipping 238 matching lines @@
 DATA_VIEW_SETTER(Uint16, uint16_t)
 DATA_VIEW_SETTER(Int16, int16_t)
 DATA_VIEW_SETTER(Uint32, uint32_t)
 DATA_VIEW_SETTER(Int32, int32_t)
 DATA_VIEW_SETTER(Float32, float)
 DATA_VIEW_SETTER(Float64, double)
 
 #undef DATA_VIEW_SETTER
 }
 }  // namespace v8::internal