VectorICs: use a vector slot to aid in array literal processing.

src/full-codegen/arm64/full-codegen-arm64.cc

Index: src/full-codegen/arm64/full-codegen-arm64.cc
diff --git a/src/full-codegen/arm64/full-codegen-arm64.cc b/src/full-codegen/arm64/full-codegen-arm64.cc
index c4f8726dc22554a10925d9697b2ccc348b87a00a..d4adb99ab94d2affb5b1a6c62b266e1c51b16ef5 100644
--- a/src/full-codegen/arm64/full-codegen-arm64.cc
+++ b/src/full-codegen/arm64/full-codegen-arm64.cc
@@ -1785,7 +1785,14 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
     }
     VisitForAccumulatorValue(subexpr);
 
-    if (has_fast_elements) {
+    if (FLAG_vector_stores) {
+      __ Mov(StoreDescriptor::NameRegister(), Smi::FromInt(array_index));
+      __ Peek(StoreDescriptor::ReceiverRegister(), kPointerSize);
+      EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
+      Handle<Code> ic =
+          CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
+      CallIC(ic);
+    } else if (has_fast_elements) {
       int offset = FixedArray::kHeaderSize + (array_index * kPointerSize);
       __ Peek(x6, kPointerSize);  // Copy of array literal.
       __ Ldr(x1, FieldMemOperand(x6, JSObject::kElementsOffset));