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

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index 7d8aa27d5eaa06857b918a0eaa9924f713528115..861018989e6a3da737c85a5886f7244116c70239 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -1753,7 +1753,14 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
     }
     VisitForAccumulatorValue(subexpr);
 
-    if (has_constant_fast_elements) {
+    if (FLAG_vector_stores) {
+      __ Move(StoreDescriptor::NameRegister(), Smi::FromInt(array_index));
+      __ movp(StoreDescriptor::ReceiverRegister(), Operand(rsp, kPointerSize));
+      EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
+      Handle<Code> ic =
+          CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
+      CallIC(ic);
+    } else if (has_constant_fast_elements) {
       // Fast-case array literal with ElementsKind of FAST_*_ELEMENTS, they
       // cannot transition and don't need to call the runtime stub.
       int offset = FixedArray::kHeaderSize + (array_index * kPointerSize);