Support fast case for-in in Crankshaft.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 3e30a4a78442f94347c74ea11e2538670ef03999..d373e191fecb81388787d74d6a9e604ee758b32a 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -2269,6 +2269,34 @@ LInstruction* LChunkBuilder::DoIn(HIn* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoForInPrepareMap(HForInPrepareMap* instr) {
+  LOperand* object = UseFixed(instr->enumerable(), rax);
+  LForInPrepareMap* result = new LForInPrepareMap(object);
+  return MarkAsCall(DefineFixed(result, rax), instr, CAN_DEOPTIMIZE_EAGERLY);
+}
+
+
+LInstruction* LChunkBuilder::DoForInCacheArray(HForInCacheArray* instr) {
+  LOperand* map = UseRegister(instr->map());
+  return AssignEnvironment(DefineAsRegister(
+      new LForInCacheArray(map)));
+}
+
+
+LInstruction* LChunkBuilder::DoCheckMapValue(HCheckMapValue* instr) {
+  LOperand* value = UseRegisterAtStart(instr->value());
+  LOperand* map = UseRegisterAtStart(instr->map());
+  return AssignEnvironment(new LCheckMapValue(value, map));
+}
+
+
+LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
+  LOperand* object = UseRegister(instr->object());
+  LOperand* index = UseTempRegister(instr->index());
+  return DefineSameAsFirst(new LLoadFieldByIndex(object, index));
+}
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64