[runtime] Allow generic allocation of sloppy arguments.

src/objects-inl.h

 // Copyright 2012 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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 2778 matching lines @@
   if (length != kInvalidEnumCacheSentinel) {
     DCHECK(length >= 0);
     DCHECK(length == 0 || instance_descriptors()->HasEnumCache());
     DCHECK(length <= NumberOfOwnDescriptors());
   }
   set_bit_field3(EnumLengthBits::update(bit_field3(), length));
 }
 
 
 FixedArrayBase* Map::GetInitialElements() {
+  FixedArrayBase* result = nullptr;
   if (has_fast_elements() || has_fast_string_wrapper_elements()) {
-    DCHECK(!GetHeap()->InNewSpace(GetHeap()->empty_fixed_array()));
-    return GetHeap()->empty_fixed_array();
+    result = GetHeap()->empty_fixed_array();
+  } else if (has_fast_sloppy_arguments_elements()) {
+    result = GetHeap()->empty_sloppy_arguments_elements();
   } else if (has_fixed_typed_array_elements()) {
-    FixedTypedArrayBase* empty_array =
-        GetHeap()->EmptyFixedTypedArrayForMap(this);
-    DCHECK(!GetHeap()->InNewSpace(empty_array));
-    return empty_array;
+    result = GetHeap()->EmptyFixedTypedArrayForMap(this);
   } else {
     UNREACHABLE();
   }
-  return NULL;
+  DCHECK(!GetHeap()->InNewSpace(result));
+  return result;
 }
 
 
 Object** DescriptorArray::GetKeySlot(int descriptor_number) {
   DCHECK(descriptor_number < number_of_descriptors());
   return RawFieldOfElementAt(ToKeyIndex(descriptor_number));
 }
 
 
 Object** DescriptorArray::GetDescriptorStartSlot(int descriptor_number) {
@@ skipping 1745 matching lines @@
 bool Map::has_fast_double_elements() {
   return IsFastDoubleElementsKind(elements_kind());
 }
 
 bool Map::has_fast_elements() { return IsFastElementsKind(elements_kind()); }
 
 bool Map::has_sloppy_arguments_elements() {
   return IsSloppyArgumentsElements(elements_kind());
 }
 
+bool Map::has_fast_sloppy_arguments_elements() {
+  return elements_kind() == FAST_SLOPPY_ARGUMENTS_ELEMENTS;
+}
+
 bool Map::has_fast_string_wrapper_elements() {
   return elements_kind() == FAST_STRING_WRAPPER_ELEMENTS;
 }
 
 bool Map::has_fixed_typed_array_elements() {
   return IsFixedTypedArrayElementsKind(elements_kind());
 }
 
 bool Map::has_dictionary_elements() {
   return IsDictionaryElementsKind(elements_kind());
@@ skipping 3296 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_