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

src/compiler/mips64/code-generator-mips64.cc

Index: src/compiler/mips64/code-generator-mips64.cc
diff --git a/src/compiler/mips64/code-generator-mips64.cc b/src/compiler/mips64/code-generator-mips64.cc
index 670bd67435cb176bfdaf9c4c45235c918002c295..bcfa56ae306a19c0bdff67ff51807be6c8296563 100644
--- a/src/compiler/mips64/code-generator-mips64.cc
+++ b/src/compiler/mips64/code-generator-mips64.cc
@@ -906,6 +906,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kCheckedLoadWord32:
       ASSEMBLE_CHECKED_LOAD_INTEGER(lw);
       break;
+    case kCheckedLoadWord64:
+      ASSEMBLE_CHECKED_LOAD_INTEGER(ld);
+      break;
     case kCheckedLoadFloat32:
       ASSEMBLE_CHECKED_LOAD_FLOAT(Single, lwc1);
       break;
@@ -921,6 +924,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kCheckedStoreWord32:
       ASSEMBLE_CHECKED_STORE_INTEGER(sw);
       break;
+    case kCheckedStoreWord64:
+      ASSEMBLE_CHECKED_STORE_INTEGER(sd);
+      break;
     case kCheckedStoreFloat32:
       ASSEMBLE_CHECKED_STORE_FLOAT(Single, swc1);
       break;