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

src/compiler/x64/instruction-selector-x64.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
@@ skipping 215 matching lines @@
   switch (rep) {
     case kRepWord8:
       opcode = typ == kTypeInt32 ? kCheckedLoadInt8 : kCheckedLoadUint8;
       break;
     case kRepWord16:
       opcode = typ == kTypeInt32 ? kCheckedLoadInt16 : kCheckedLoadUint16;
       break;
     case kRepWord32:
       opcode = kCheckedLoadWord32;
       break;
+    case kRepWord64:
+      opcode = kCheckedLoadWord64;
+      break;
     case kRepFloat32:
       opcode = kCheckedLoadFloat32;
       break;
     case kRepFloat64:
       opcode = kCheckedLoadFloat64;
       break;
     default:
       UNREACHABLE();
       return;
   }
@@ skipping 27 matching lines @@
   switch (rep) {
     case kRepWord8:
       opcode = kCheckedStoreWord8;
       break;
     case kRepWord16:
       opcode = kCheckedStoreWord16;
       break;
     case kRepWord32:
       opcode = kCheckedStoreWord32;
       break;
+    case kRepWord64:
+      opcode = kCheckedStoreWord64;
+      break;
     case kRepFloat32:
       opcode = kCheckedStoreFloat32;
       break;
     case kRepFloat64:
       opcode = kCheckedStoreFloat64;
       break;
     default:
       UNREACHABLE();
       return;
   }
@@ skipping 1385 matching lines @@
   if (CpuFeatures::IsSupported(SSE4_1)) {
     flags |= MachineOperatorBuilder::kFloat64RoundDown |
              MachineOperatorBuilder::kFloat64RoundTruncate;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8