[turbofan] support for Int64 in CheckedLoad/CheckedStore on 64-bit platforms.

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index 76b1059eb58ca19e9954509c4528593d10c669ae..fbc7df27e3157e33347a507d9769b86245865c5a 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -458,6 +458,9 @@ void InstructionSelector::VisitCheckedLoad(Node* node) {
     case kRepWord32:
       opcode = kCheckedLoadWord32;
       break;
+    case kRepWord64:
+      opcode = kCheckedLoadWord64;
+      break;
     case kRepFloat32:
       opcode = kCheckedLoadFloat32;
       break;
@@ -491,6 +494,9 @@ void InstructionSelector::VisitCheckedStore(Node* node) {
     case kRepWord32:
       opcode = kCheckedStoreWord32;
       break;
+    case kRepWord64:
+      opcode = kCheckedStoreWord64;
+      break;
     case kRepFloat32:
       opcode = kCheckedStoreFloat32;
       break;