[runtime] Avoid @@isConcatSpreadable lookup for fast path Array.prototype.concat

src/crankshaft/x64/lithium-codegen-x64.cc

Index: src/crankshaft/x64/lithium-codegen-x64.cc
diff --git a/src/crankshaft/x64/lithium-codegen-x64.cc b/src/crankshaft/x64/lithium-codegen-x64.cc
index 335591899bbbe5605fe579b2438b3a86dc6b507c..620b5f9d27877ca35bd37f82a3816c210c3e3382 100644
--- a/src/crankshaft/x64/lithium-codegen-x64.cc
+++ b/src/crankshaft/x64/lithium-codegen-x64.cc
@@ -3121,11 +3121,12 @@ void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
     __ j(not_equal, &done);
     if (info()->IsStub()) {
       // A stub can safely convert the hole to undefined only if the array
-      // protector cell contains (Smi) Isolate::kArrayProtectorValid. Otherwise
+      // protector cell contains (Smi) Isolate::kArrayElementsProtectorValid.
+      // Otherwise
       // it needs to bail out.
-      __ LoadRoot(result, Heap::kArrayProtectorRootIndex);
+      __ LoadRoot(result, Heap::kArrayElementsProtectorRootIndex);
       __ Cmp(FieldOperand(result, Cell::kValueOffset),
-             Smi::FromInt(Isolate::kArrayProtectorValid));
+             Smi::FromInt(Isolate::kArrayElementsProtectorValid));
       DeoptimizeIf(not_equal, instr, Deoptimizer::kHole);
     }
     __ Move(result, isolate()->factory()->undefined_value());