[elements, turbofan] Implement simple GrowElements

src/runtime/runtime-array.cc

Index: src/runtime/runtime-array.cc
diff --git a/src/runtime/runtime-array.cc b/src/runtime/runtime-array.cc
index 3c5e817de9a5e124c7a58827a771b76a3d2b1c36..eee6a8664eb996db6c42749268037fe7053c0118 100644
--- a/src/runtime/runtime-array.cc
+++ b/src/runtime/runtime-array.cc
@@ -374,15 +374,10 @@ RUNTIME_FUNCTION(Runtime_GrowArrayElements) {
   uint32_t index = static_cast<uint32_t>(key);
 
   if (index >= capacity) {
-    if (object->map()->is_prototype_map() ||
-        object->WouldConvertToSlowElements(index)) {
-      // We don't want to allow operations that cause lazy deopt. Return a Smi
-      // as a signal that optimized code should eagerly deoptimize.
+    uint32_t new_capacity = JSObject::NewElementsCapacity(index + 1);
+    if (!object->GetElementsAccessor()->GrowCapacity(object, new_capacity)) {
       return Smi::FromInt(0);
     }
-
-    uint32_t new_capacity = JSObject::NewElementsCapacity(index + 1);
-    object->GetElementsAccessor()->GrowCapacityAndConvert(object, new_capacity);
   }
 
   // On success, return the fixed array elements.