Remove LeftTrimFixedArray

src/elements.cc

Index: src/elements.cc
diff --git a/src/elements.cc b/src/elements.cc
index 32e6605ca2fbd04d07a80a387a825c6bec346482..c6d47d9a8df87c5640425bf27a9b529b98de2e12 100644
--- a/src/elements.cc
+++ b/src/elements.cc
@@ -1337,12 +1337,8 @@ class FastElementsAccessor
     Handle<Object> result =
         FastElementsAccessorSubclass::GetImpl(backing_store, 0);
     Heap* heap = isolate->heap();
-    if (heap->CanMoveObjectStart(*backing_store)) {
-      receiver->set_elements(heap->LeftTrimFixedArray(*backing_store, 1));
-    } else {
-      FastElementsAccessorSubclass::MoveElements(heap, backing_store, 0, 1,
-                                                 new_length, 0, 0);
-    }
+    FastElementsAccessorSubclass::MoveElements(heap, backing_store, 0, 1,
+                                               new_length, 0, 0);
     FastElementsAccessorSubclass::SetLengthImpl(receiver, new_length,
                                                 backing_store);
 
@@ -1509,22 +1505,9 @@ class FastElementsAccessor
                                uint32_t len, uint32_t new_length) {
     const int move_left_count = len - delete_count - start;
     const int move_left_dst_index = start + add_count;
-    const bool left_trim_array = heap->CanMoveObjectStart(*backing_store) &&
-                                 (move_left_dst_index < move_left_count);
-    if (left_trim_array) {
-      const int delta = delete_count - add_count;
-      // shift from before the insertion point to the right
-      FastElementsAccessorSubclass::MoveElements(heap, backing_store, delta, 0,
-                                                 start, 0, 0);
-      backing_store = handle(heap->LeftTrimFixedArray(*backing_store, delta));
-      return true;
-    } else {
-      // No left-trim needed or possible (in this case we left-move and store
-      // the hole)
-      FastElementsAccessorSubclass::MoveElements(
-          heap, backing_store, move_left_dst_index, start + delete_count,
-          move_left_count, new_length, len);
-    }
+    FastElementsAccessorSubclass::MoveElements(
+        heap, backing_store, move_left_dst_index, start + delete_count,
+        move_left_count, new_length, len);
     return false;
   }