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

src/compiler/ppc/code-generator-ppc.cc

Index: src/compiler/ppc/code-generator-ppc.cc
diff --git a/src/compiler/ppc/code-generator-ppc.cc b/src/compiler/ppc/code-generator-ppc.cc
index 83b857eeb9f8d1c41503d1ed90e2b897964007a7..3d99b06eb91efb400042fb2f456b1830ab6718f2 100644
--- a/src/compiler/ppc/code-generator-ppc.cc
+++ b/src/compiler/ppc/code-generator-ppc.cc
@@ -1142,6 +1142,13 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kCheckedLoadWord32:
       ASSEMBLE_CHECKED_LOAD_INTEGER(lwa, lwax);
       break;
+    case kCheckedLoadWord64:
+#if V8_TARGET_ARCH_PPC64
+      ASSEMBLE_CHECKED_LOAD_INTEGER(ld, ldx);
+#else
+      UNREACHABLE();
+#endif
+      break;
     case kCheckedLoadFloat32:
       ASSEMBLE_CHECKED_LOAD_FLOAT(lfs, lfsx, 32);
       break;
@@ -1157,6 +1164,13 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kCheckedStoreWord32:
       ASSEMBLE_CHECKED_STORE_INTEGER(stw, stwx);
       break;
+    case kCheckedStoreWord64:
+#if V8_TARGET_ARCH_PPC64
+      ASSEMBLE_CHECKED_STORE_INTEGER(std, stdx);
+#else
+      UNREACHABLE();
+#endif
+      break;
     case kCheckedStoreFloat32:
       ASSEMBLE_CHECKED_STORE_FLOAT32();
       break;